Update recipes builders to use python 3.

These builders were never migrated to use python3.

Change-Id: Ib4a96002d1e3fe838cbe911f67a115e539133e78
Reviewed-on: https://flutter-review.googlesource.com/c/infra/+/24743
Reviewed-by: Keyong Han <keyonghan@google.com>
Commit-Queue: Godofredo Contreras <godofredoc@google.com>
diff --git a/config/generated/flutter/luci/cr-buildbucket.cfg b/config/generated/flutter/luci/cr-buildbucket.cfg
index af5a32d..c60b4be 100644
--- a/config/generated/flutter/luci/cr-buildbucket.cfg
+++ b/config/generated/flutter/luci/cr-buildbucket.cfg
@@ -105148,6 +105148,10 @@
       service_account: "flutter-prod-builder@chops-service-accounts.iam.gserviceaccount.com"
       task_template_canary_percentage {}
       experiments {
+        key: "luci.recipes.use_python3"
+        value: 100
+      }
+      experiments {
         key: "luci.use_realms"
         value: 100
       }
@@ -105193,6 +105197,10 @@
       service_account: "flutter-prod-builder@chops-service-accounts.iam.gserviceaccount.com"
       task_template_canary_percentage {}
       experiments {
+        key: "luci.recipes.use_python3"
+        value: 100
+      }
+      experiments {
         key: "luci.use_realms"
         value: 100
       }
@@ -146059,6 +146067,10 @@
       service_account: "flutter-try-builder@chops-service-accounts.iam.gserviceaccount.com"
       task_template_canary_percentage {}
       experiments {
+        key: "luci.recipes.use_python3"
+        value: 100
+      }
+      experiments {
         key: "luci.use_realms"
         value: 100
       }
@@ -146100,6 +146112,10 @@
       service_account: "flutter-try-builder@chops-service-accounts.iam.gserviceaccount.com"
       task_template_canary_percentage {}
       experiments {
+        key: "luci.recipes.use_python3"
+        value: 100
+      }
+      experiments {
         key: "luci.use_realms"
         value: 100
       }
@@ -146149,6 +146165,10 @@
       service_account: "flutter-try-builder@chops-service-accounts.iam.gserviceaccount.com"
       task_template_canary_percentage {}
       experiments {
+        key: "luci.recipes.use_python3"
+        value: 100
+      }
+      experiments {
         key: "luci.use_realms"
         value: 100
       }
diff --git a/config/recipes_config.star b/config/recipes_config.star
index 8c380d5..c4d3a91 100644
--- a/config/recipes_config.star
+++ b/config/recipes_config.star
@@ -59,6 +59,7 @@
             "unittest_only": True,
         },
         service_account = accounts.FLUTTER_TRY,
+        experiments = {"luci.recipes.use_python3": 100},
     )
 
     # Builder configuration to run led tasks of all affected recipes.
@@ -76,6 +77,7 @@
             "os": "Linux",
         },
         service_account = accounts.FLUTTER_TRY,
+        experiments = {"luci.recipes.use_python3": 100},
     )
 
     common.builder(
@@ -96,6 +98,7 @@
             "cipd_packages": [{"name": "infra/tools/yapf", "subdir": "", "version": "latest"}],
         },
         service_account = accounts.FLUTTER_TRY,
+        experiments = {"luci.recipes.use_python3": 100},
     )
 
     # Postsubmit builders.
@@ -125,6 +128,7 @@
         schedule = "0 2,13 * * *",
         console_category = console_name,
         console_short_name = "aroll",
+        experiments = {"luci.recipes.use_python3": 100},
     )
 
     # Recipes builder. This is used to create a bundle of the cipd package.
@@ -153,6 +157,7 @@
         }.items(),
         console_category = console_name,
         console_short_name = "bdlr",
+        experiments = {"luci.recipes.use_python3": 100},
     )
 
 recipes_config = struct(setup = _setup)