The slowness issue was resolved with latest xcode: https://github.com/flutter/flutter/issues/119750, and all these targets should resume on both platforms as before. This will help mitigate high queue time on intel bots.

This PR updates these targets:

- Mac plugin_test_ios: https://github.com/flutter/flutter/issues/119764
- Mac build_tests: https://github.com/flutter/flutter/pull/120620
- Mac plugin_test: https://github.com/flutter/flutter/pull/120714
- Mac plugin_test_macos: https://github.com/flutter/flutter/pull/122212
- Mac framework_tests_misc: https://github.com/flutter/flutter/pull/122618