Reverts "Add Mac cache_builder back into Prod" (#49961)

Reverts #49936
Initiated by: zanderso
This change reverts the following previous change:
Original Description:
Add the Mac cache_builder target back to prod.

*List which issues are fixed by this PR. You must list at least one issue.*
Fixes flutter/flutter#141688

*If you had to change anything in the [flutter/tests] repo, include a link to the migration guide as per the [breaking change policy].*

[C++, Objective-C, Java style guides]: https://github.com/flutter/engine/blob/main/CONTRIBUTING.md#style

.ci.yaml

@@ -115,6 +115,7 @@ targets:
     timeout: 60
 
   - name: Mac builder_cache
+    bringup: true
     enabled_branches:
       - main
     recipe: engine_v2/cache