Environment variables for not outputting the terminal output of a cached task

[chabb]

We've some unit tests that are emitting a lot of logs.
This unfortunately breaks STDOUT on gitlab when caching is used, I guess it's because 15'000 lines are outputted all at once, and the gitlab runner is not able to display the logs.

It would be nice to have a flag ( environment variables, or some options in the project.json ) that would disable logging for cached task ( after all, we know the result of a cached task ). This would unblock us