Only run CSS and JS lint jobs if files have changed

MR!6504 pipeline should show the CSS and JS lint jobs being skipped. The other two MRs should run one of the jobs as required.

@catch suggested skipping some of the PHP jobs in a similar way, but I think we have to be more careful; for example tests can rely on pretty much any file in the repo as a fixture, and we would want to rerun the tests if these are changed. I think we can probably skip PHPStan based on file extension, but let's explore that in a followup.

+1 to merging the compilation check, it won't add any real time to pipelines but it'll save a minute or so of runner time every job.

It is slightly disconcerting seeing less jobs, even though I was explicitly reviewing this MR I was thinking "where've they gone!". I'm not sure if we want to leave something in their place when they're skipped (like the 'manual' button) just for consistency?

Yeah, let's add a manual button, then we can run then in special extra cases too if we need to.

I see a skipped CSS run on https://git.drupalcode.org/project/drupal/-/pipelines/90615 but not eslint, however is that because eslint is linting the YAML that we're changing in the MR? If so, RTBC for me.

Yes, I realised that ESLint also covers YAML, and added it to the set of changed file patterns, so it runs on this MR now.

(PHPCS also lints YAML, but we should probably stop doing that now ESLint does a better job)

OK this is great then, we might find other things later, but can sort that out later.

Skipping YAML in the phpcs job seems like a good idea but can be its own issue.

Committed/pushed to 11.x and cherry-picked to 10.2.x, thanks!

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