Allow macOS tests to use macOS 15 or 26 (#193317)

Part of https://github.com/flutter/flutter/issues/192568

The following tests are kept on 15 due to failing testing. We will fix
once we have macOS 26 bots in the try pool:
* Mac framework_tests_libraries
* Mac framework_tests_impeller
* Mac framework_tests_widgets
* Mac_build_test flutter_gallery__transition_perf_e2e_ios
* Mac mac_unopt < ci/mac_release_arm64_tests
* Linux linux_web_engine_tests < Mac run safari suites

## Pre-launch Checklist

- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [AI contribution guidelines] and understand my
responsibilities, or I am not using AI tools.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant in-code documentation (doc comments with
`///`).
- [x] If this PR introduces a new feature or capability, I created and
linked a website documentation issue or PR in [flutter/website] (or
verified none is needed).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.

If you need help, consider asking for advice on the #hackers-new channel
on [Discord].

If this change needs to override an active code freeze, provide a
comment explaining why. The code freeze workflow can be overridden by
code reviewers. See pinned issues for any active code freezes with
guidance.

**Note**: The Flutter team is currently trialing the use of [Gemini Code
Assist for
GitHub](https://developers.google.com/gemini-code-assist/docs/review-github-code).
Comments from the `gemini-code-assist` bot should not be taken as
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useful you can update your code accordingly, but if you are unsure or
disagree with the feedback, please feel free to wait for a Flutter team
member's review for guidance on which automated comments should be
addressed.

<!-- Links -->
[Contributor Guide]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#overview
[AI contribution guidelines]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#ai-contribution-guidelines
[Tree Hygiene]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md
[test-exempt]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#tests
[Flutter Style Guide]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md
[Features we expect every widget to implement]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md#features-we-expect-every-widget-to-implement
[CLA]: https://cla.developers.google.com/
[flutter/tests]: https://github.com/flutter/tests
[flutter/website]: https://github.com/flutter/website
[breaking change policy]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#handling-breaking-changes
[Discord]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Chat.md
[Data Driven Fixes]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Data-driven-Fixes.md

---------

Co-authored-by: Jackson Gardner <jacksongardner@google.com>
diff --git a/.ci.yaml b/.ci.yaml
index 6597fe5..3a17ff7 100644
--- a/.ci.yaml
+++ b/.ci.yaml
@@ -175,7 +175,7 @@
         [
           {"dependency": "apple_signing", "version": "version:to_2027"}
         ]
-      os: Mac-15.7
+      os: Mac-15.7|Mac-26.6
       device_type: none
       $flutter/osx_sdk : >-
         {
@@ -192,7 +192,7 @@
         [
           {"dependency": "apple_signing", "version": "version:to_2027"}
         ]
-      os: Mac-15.7
+      os: Mac-15.7|Mac-26.6
       device_type: none
       cpu: arm64
       $flutter/osx_sdk : >-
@@ -217,7 +217,7 @@
       # (https://flutter.dev/go/macos-intel-deprecation).
       mac_model: "Macmini9,1"
       cpu: arm64
-      os: Mac-15.7
+      os: Mac-15.7|Mac-26.6
       tags: >
         ["devicelab", "hostonly", "mac", "arm64"]
       $flutter/osx_sdk : >-
@@ -235,7 +235,7 @@
         [
           {"dependency": "apple_signing", "version": "version:to_2027"}
         ]
-      os: Mac-15.7
+      os: Mac-15.7|Mac-26.6
       device_type: none
       cpu: x86
       $flutter/osx_sdk : >-
@@ -271,7 +271,7 @@
           {"dependency": "open_jdk", "version": "version:21"},
           {"dependency": "gradle_dists", "version": "8.4-bin:8.13-rc-1-bin:8.14-bin:9.3.1-bin:9.3.1-all"}
         ]
-      os: Mac-15.7
+      os: Mac-15.7|Mac-26.6
       cpu: x86
       device_type: "mokey"
 
@@ -283,7 +283,7 @@
           {"dependency": "open_jdk", "version": "version:21"},
           {"dependency": "gradle_dists", "version": "8.4-bin:8.13-rc-1-bin:8.14-bin:9.3.1-bin:9.3.1-all"}
         ]
-      os: Mac-15.7
+      os: Mac-15.7|Mac-26.6
       cpu: arm64
       device_type: "mokey"
 
@@ -298,7 +298,7 @@
           {"dependency": "ruby", "version": "ruby_3.1-pod_1.13"},
           {"dependency": "apple_signing", "version": "version:to_2027"}
         ]
-      os: Mac-15.7
+      os: Mac-15.7|Mac-26.6
       device_os: iOS-18|iOS-26
       $flutter/osx_sdk : >-
         {
@@ -316,7 +316,7 @@
           {"dependency": "ruby", "version": "ruby_3.1-pod_1.13"},
           {"dependency": "apple_signing", "version": "version:to_2027"}
         ]
-      os: Mac-15.7
+      os: Mac-15.7|Mac-26.6
       cpu: x86
       device_os: iOS-18|iOS-26
       $flutter/osx_sdk : >-
@@ -335,7 +335,7 @@
           {"dependency": "ruby", "version": "ruby_3.1-pod_1.13"},
           {"dependency": "apple_signing", "version": "none"}
         ]
-      os: Mac-15.7
+      os: Mac-15.7|Mac-26.6
       cpu: arm64
       device_os: iOS-18|iOS-26
       $flutter/osx_sdk : >-
@@ -4236,6 +4236,7 @@
     recipe: flutter/flutter_drone
     timeout: 60
     properties:
+      os: Mac-15.7 # https://github.com/flutter/flutter/issues/193155
       cpu: arm64 # https://github.com/flutter/flutter/issues/119880
       dependencies: >-
         [
@@ -4264,6 +4265,7 @@
     recipe: flutter/flutter_drone
     timeout: 60
     properties:
+      os: Mac-15.7 # https://github.com/flutter/flutter/issues/193157
       cpu: arm64 # https://github.com/flutter/flutter/issues/119880
       dependencies: >-
         [
@@ -4359,6 +4361,7 @@
     recipe: flutter/flutter_drone
     timeout: 60
     properties:
+      os: Mac-15.7 # https://github.com/flutter/flutter/issues/193158
       cpu: arm64 # https://github.com/flutter/flutter/issues/119880
       dependencies: >-
         [
diff --git a/engine/src/flutter/.ci.yaml b/engine/src/flutter/.ci.yaml
index ca4edbb..9aabbb0 100644
--- a/engine/src/flutter/.ci.yaml
+++ b/engine/src/flutter/.ci.yaml
@@ -31,7 +31,7 @@
           {"dependency": "open_jdk", "version": "version:21"}
         ]
       device_type: none
-      os: Mac-15.7
+      os: Mac-15.7|Mac-26.6
       $flutter/osx_sdk : >-
         {
           "sdk_version": "17c52"
@@ -491,7 +491,7 @@
     # Do not remove(https://github.com/flutter/flutter/issues/144644)
     # Scheduler will fail to get the platform
     drone_dimensions:
-      - os=Mac-15.7
+      - os=Mac-15.7|Mac-26.6
 
   - name: Mac clangd
     recipe: engine_v2/builder
@@ -520,7 +520,7 @@
     # Do not remove(https://github.com/flutter/flutter/issues/144644)
     # Scheduler will fail to get the platform
     drone_dimensions:
-      - os=Mac-15.7
+      - os=Mac-15.7|Mac-26.6
       - cpu=x86
 
   - name: Mac mac_ios_engine_ddm
@@ -540,7 +540,7 @@
     # Do not remove(https://github.com/flutter/flutter/issues/144644)
     # Scheduler will fail to get the platform
     drone_dimensions:
-      - os=Mac-15.7
+      - os=Mac-15.7|Mac-26.6
       - cpu=x86
 
   - name: Linux windows_android_aot_engine
diff --git a/engine/src/flutter/ci/builders/local_engine.json b/engine/src/flutter/ci/builders/local_engine.json
index 5aee732..7d27bbb 100644
--- a/engine/src/flutter/ci/builders/local_engine.json
+++ b/engine/src/flutter/ci/builders/local_engine.json
@@ -3,7 +3,7 @@
     {
       "cas_archive": false,
       "drone_dimensions": [
-        "os=Mac-15.7",
+        "os=Mac-15.7|Mac-26.6",
         "device_type=none"
       ],
       "gclient_variables": {
@@ -36,7 +36,7 @@
     {
       "cas_archive": false,
       "drone_dimensions": [
-        "os=Mac-15.7",
+        "os=Mac-15.7|Mac-26.6",
         "device_type=none"
       ],
       "gclient_variables": {
@@ -70,7 +70,7 @@
     {
       "cas_archive": false,
       "drone_dimensions": [
-        "os=Mac-15.7",
+        "os=Mac-15.7|Mac-26.6",
         "device_type=none"
       ],
       "gclient_variables": {
@@ -103,7 +103,7 @@
     {
       "cas_archive": false,
       "drone_dimensions": [
-        "os=Mac-15.7",
+        "os=Mac-15.7|Mac-26.6",
         "device_type=none"
       ],
       "gclient_variables": {
@@ -136,7 +136,7 @@
     {
       "cas_archive": false,
       "drone_dimensions": [
-        "os=Mac-15.7",
+        "os=Mac-15.7|Mac-26.6",
         "device_type=none"
       ],
       "gclient_variables": {
@@ -170,7 +170,7 @@
     {
       "cas_archive": false,
       "drone_dimensions": [
-        "os=Mac-15.7",
+        "os=Mac-15.7|Mac-26.6",
         "device_type=none"
       ],
       "gclient_variables": {
@@ -206,7 +206,7 @@
     {
       "cas_archive": false,
       "drone_dimensions": [
-        "os=Mac-15.7",
+        "os=Mac-15.7|Mac-26.6",
         "device_type=none"
       ],
       "gclient_variables": {
@@ -370,7 +370,7 @@
     {
       "cas_archive": false,
       "drone_dimensions": [
-        "os=Mac-15.7",
+        "os=Mac-15.7|Mac-26.6",
         "device_type=none"
       ],
       "gclient_variables": {
@@ -403,7 +403,7 @@
     {
       "cas_archive": false,
       "drone_dimensions": [
-        "os=Mac-15.7",
+        "os=Mac-15.7|Mac-26.6",
         "device_type=none"
       ],
       "gclient_variables": {
@@ -436,7 +436,7 @@
     {
       "cas_archive": false,
       "drone_dimensions": [
-        "os=Mac-15.7",
+        "os=Mac-15.7|Mac-26.6",
         "device_type=none"
       ],
       "gclient_variables": {
@@ -520,7 +520,7 @@
     {
       "cas_archive": false,
       "drone_dimensions": [
-        "os=Mac-15.7",
+        "os=Mac-15.7|Mac-26.6",
         "device_type=none"
       ],
       "gclient_variables": {
@@ -604,7 +604,7 @@
     {
       "cas_archive": false,
       "drone_dimensions": [
-        "os=Mac-15.7",
+        "os=Mac-15.7|Mac-26.6",
         "device_type=none"
       ],
       "gclient_variables": {
@@ -636,7 +636,7 @@
     {
       "cas_archive": false,
       "drone_dimensions": [
-        "os=Mac-15.7",
+        "os=Mac-15.7|Mac-26.6",
         "device_type=none"
       ],
       "gclient_variables": {
@@ -669,7 +669,7 @@
     {
       "cas_archive": false,
       "drone_dimensions": [
-        "os=Mac-15.7",
+        "os=Mac-15.7|Mac-26.6",
         "device_type=none"
       ],
       "gclient_variables": {
@@ -702,7 +702,7 @@
     {
       "cas_archive": false,
       "drone_dimensions": [
-        "os=Mac-15.7",
+        "os=Mac-15.7|Mac-26.6",
         "device_type=none"
       ],
       "gclient_variables": {
@@ -841,7 +841,7 @@
     {
       "cas_archive": false,
       "drone_dimensions": [
-        "os=Mac-15.7",
+        "os=Mac-15.7|Mac-26.6",
         "device_type=none"
       ],
       "gclient_variables": {
@@ -925,7 +925,7 @@
     {
       "cas_archive": false,
       "drone_dimensions": [
-        "os=Mac-15.7",
+        "os=Mac-15.7|Mac-26.6",
         "device_type=none"
       ],
       "gclient_variables": {
@@ -1063,7 +1063,7 @@
       "name": "macos/wasm_release",
       "drone_dimensions": [
         "device_type=none",
-        "os=Mac-15.7",
+        "os=Mac-15.7|Mac-26.6",
         "cpu=arm64"
       ],
       "gclient_variables": {
@@ -1100,7 +1100,7 @@
       "name": "macos/wasm_debug_unopt",
       "drone_dimensions": [
         "device_type=none",
-        "os=Mac-15.7",
+        "os=Mac-15.7|Mac-26.6",
         "cpu=arm64"
       ],
       "gclient_variables": {
diff --git a/engine/src/flutter/ci/builders/mac_android_aot_engine.json b/engine/src/flutter/ci/builders/mac_android_aot_engine.json
index a71ef35..86170d5 100644
--- a/engine/src/flutter/ci/builders/mac_android_aot_engine.json
+++ b/engine/src/flutter/ci/builders/mac_android_aot_engine.json
@@ -25,7 +25,7 @@
             ],
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=x86"
             ],
             "gclient_variables": {
@@ -83,7 +83,7 @@
             ],
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=x86"
             ],
             "gclient_variables": {
@@ -143,7 +143,7 @@
             ],
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=x86"
             ],
             "gclient_variables": {
@@ -203,7 +203,7 @@
             ],
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=x86"
             ],
             "gclient_variables": {
@@ -261,7 +261,7 @@
             ],
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=x86"
             ],
             "gclient_variables": {
@@ -321,7 +321,7 @@
             ],
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=x86"
             ],
             "gclient_variables": {
diff --git a/engine/src/flutter/ci/builders/mac_clang_tidy.json b/engine/src/flutter/ci/builders/mac_clang_tidy.json
index be8f1df..83b4557 100644
--- a/engine/src/flutter/ci/builders/mac_clang_tidy.json
+++ b/engine/src/flutter/ci/builders/mac_clang_tidy.json
@@ -3,7 +3,7 @@
         {
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -36,7 +36,7 @@
         {
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -74,7 +74,7 @@
             "recipe": "engine_v2/tester_engine",
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -129,7 +129,7 @@
             "recipe": "engine_v2/tester_engine",
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -184,7 +184,7 @@
             "recipe": "engine_v2/tester_engine",
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -239,7 +239,7 @@
             "recipe": "engine_v2/tester_engine",
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -294,7 +294,7 @@
             "recipe": "engine_v2/tester_engine",
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=arm64"
             ],
             "gclient_variables": {
diff --git a/engine/src/flutter/ci/builders/mac_host_engine.json b/engine/src/flutter/ci/builders/mac_host_engine.json
index 91ba3fd..37af67d 100644
--- a/engine/src/flutter/ci/builders/mac_host_engine.json
+++ b/engine/src/flutter/ci/builders/mac_host_engine.json
@@ -17,7 +17,7 @@
         {
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -84,7 +84,7 @@
             ],
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -140,7 +140,7 @@
         {
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -205,7 +205,7 @@
             ],
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -256,7 +256,7 @@
         {
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -307,7 +307,7 @@
         {
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -370,7 +370,7 @@
             ],
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -424,7 +424,7 @@
         {
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -477,7 +477,7 @@
         {
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -543,7 +543,7 @@
             ],
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -600,7 +600,7 @@
         {
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -656,7 +656,7 @@
         {
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -722,7 +722,7 @@
             ],
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -777,7 +777,7 @@
         {
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -832,7 +832,7 @@
         {
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -899,7 +899,7 @@
             ],
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -957,7 +957,7 @@
         {
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -1014,7 +1014,7 @@
         {
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=arm64"
             ],
             "gclient_variables": {
diff --git a/engine/src/flutter/ci/builders/mac_ios_engine.json b/engine/src/flutter/ci/builders/mac_ios_engine.json
index fc2dc62..770ab69 100644
--- a/engine/src/flutter/ci/builders/mac_ios_engine.json
+++ b/engine/src/flutter/ci/builders/mac_ios_engine.json
@@ -14,7 +14,7 @@
         {
             "drone_dimensions": [
                 "device_os=ignore_phone|none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -61,7 +61,7 @@
         {
             "drone_dimensions": [
                 "device_os=ignore_phone|none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -110,7 +110,7 @@
         {
             "drone_dimensions": [
                 "device_os=ignore_phone|none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -157,7 +157,7 @@
         {
             "drone_dimensions": [
                 "device_os=ignore_phone|none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -204,7 +204,7 @@
         {
             "drone_dimensions": [
                 "device_os=ignore_phone|none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -251,7 +251,7 @@
         {
             "drone_dimensions": [
                 "device_os=ignore_phone|none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -300,7 +300,7 @@
         {
             "drone_dimensions": [
                 "device_os=ignore_phone|none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -351,7 +351,7 @@
         {
             "drone_dimensions": [
                 "device_os=ignore_phone|none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -400,7 +400,7 @@
         {
             "drone_dimensions": [
                 "device_os=ignore_phone|none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -449,7 +449,7 @@
         {
             "drone_dimensions": [
                 "device_os=ignore_phone|none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=arm64"
             ],
             "gclient_variables": {
diff --git a/engine/src/flutter/ci/builders/mac_ios_engine_ddm.json b/engine/src/flutter/ci/builders/mac_ios_engine_ddm.json
index 81120ce..f772e92 100644
--- a/engine/src/flutter/ci/builders/mac_ios_engine_ddm.json
+++ b/engine/src/flutter/ci/builders/mac_ios_engine_ddm.json
@@ -14,7 +14,7 @@
     {
       "drone_dimensions": [
         "device_type=none",
-        "os=Mac-15.7",
+        "os=Mac-15.7|Mac-26.6",
         "cpu=arm64"
       ],
       "gclient_variables": {
@@ -63,7 +63,7 @@
     {
       "drone_dimensions": [
         "device_type=none",
-        "os=Mac-15.7",
+        "os=Mac-15.7|Mac-26.6",
         "cpu=arm64"
       ],
       "gclient_variables": {
@@ -114,7 +114,7 @@
     {
       "drone_dimensions": [
         "device_type=none",
-        "os=Mac-15.7",
+        "os=Mac-15.7|Mac-26.6",
         "cpu=arm64"
       ],
       "gclient_variables": {
@@ -163,7 +163,7 @@
     {
       "drone_dimensions": [
         "device_type=none",
-        "os=Mac-15.7",
+        "os=Mac-15.7|Mac-26.6",
         "cpu=arm64"
       ],
       "gclient_variables": {
diff --git a/engine/src/flutter/ci/builders/mac_unopt.json b/engine/src/flutter/ci/builders/mac_unopt.json
index b90abe9..d8ca004 100644
--- a/engine/src/flutter/ci/builders/mac_unopt.json
+++ b/engine/src/flutter/ci/builders/mac_unopt.json
@@ -4,7 +4,7 @@
             "cas_archive": false,
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -57,7 +57,7 @@
             "cas_archive": false,
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -108,7 +108,7 @@
             "cas_archive": false,
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -159,7 +159,7 @@
             "cas_archive": false,
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -267,7 +267,7 @@
             "cas_archive": false,
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -336,7 +336,7 @@
             },
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -404,7 +404,7 @@
             },
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-15.7",
+                "os=Mac-15.7|Mac-26.6",
                 "cpu=arm64"
             ],
             "gclient_variables": {