Move Gitlab linting steps to main job

Posponed on 📌 Configure GitLabCI matrix testing Active

Remove phpstan step since @longwave and @catch decided we can wait on that until we see real reason to.

I've moved the lint stept to the parent pipeline. Things should be linted before we start child jobs.

There are no lint jobs in the child jobs anymore. But we do have an extra composer/yarn run now in the parent job. But i think that is a good tradeoff.

Not sure how to completely test this. Will add a new branch with errors from ✨ Integrate codequality reports into Gitlab RTBC to proove failure.

All green.

Looks great when it's not messed up by me...

Will commit Monday if no further feedback by then to unblock the next steps.

Committed/pushed to 11.x and cherry-picked to 10.1.x, thanks!

Wondering what it would look like if we moved the default environment test runs into the main job too, and only used child jobs for non-default environments. It would block non-default environments on a default-environment pass, and mean the common case of an MR pipeline running against the default wouldn't need the double build step. However no idea how to structure this cleanly in the YAML, and it would have other issues like having to wait for MySQL if you're actually testing a postgres bug.

Automatically closed - issue fixed for 2 weeks with no activity.