Enable Mac Web Engine in recipes tests. (#31623)
Enable Mac Web Engine in recipes tests. (#31623)

This is required to test this builder on the recipes changes.
jason-simmons/flutter_engine,rmacnak-google/engine,devoncarew/engine,flutter/engine,devoncarew/engine,jason-simmons/flutter_engine,jason-simmons/flutter_engine,chinmaygarde/flutter_engine,rmacnak-google/engine,rmacnak-google/engine,jason-simmons/flutter_engine,rmacnak-google/engine,jason-simmons/flutter_engine,devoncarew/engine,jason-simmons/flutter_engine,rmacnak-google/engine,devoncarew/engine,chinmaygarde/flutter_engine,chinmaygarde/flutter_engine,jason-simmons/flutter_engine,flutter/engine,devoncarew/engine,devoncarew/engine,chinmaygarde/flutter_engine,jason-simmons/flutter_engine,chinmaygarde/flutter_engine,devoncarew/engine,flutter/engine,flutter/engine,rmacnak-google/engine,chinmaygarde/flutter_engine,flutter/engine,flutter/engine,rmacnak-google/engine,flutter/engine,flutter/engine,chinmaygarde/flutter_engine