Force `Mac tool_integration_tests` to run on x64 bots (#120634)

.ci.yaml

diff --git a/.ci.yaml b/.ci.yaml
index bf712d5..b947a52 100644
--- a/.ci.yaml
+++ b/.ci.yaml
@@ -3081,6 +3081,7 @@
     recipe: flutter/flutter_drone
     timeout: 60
     properties:
+      cpu: x86 # https://github.com/flutter/flutter/issues/120014
       add_recipes_cq: "true"
       dependencies: >-
         [
@@ -3106,6 +3107,7 @@
     recipe: flutter/flutter_drone
     timeout: 60
     properties:
+      cpu: x86 # https://github.com/flutter/flutter/issues/120014
       add_recipes_cq: "true"
       dependencies: >-
         [
@@ -3131,6 +3133,7 @@
     recipe: flutter/flutter_drone
     timeout: 60
     properties:
+      cpu: x86 # https://github.com/flutter/flutter/issues/120014
       add_recipes_cq: "true"
       dependencies: >-
         [
@@ -3156,6 +3159,7 @@
     recipe: flutter/flutter_drone
     timeout: 60
     properties:
+      cpu: x86 # https://github.com/flutter/flutter/issues/120014
       add_recipes_cq: "true"
       dependencies: >-
         [