This skips the `make compile-requirements` check when there have been
no changes under `requirements/**`, but it does so in a way that still
registers the action as having passed, not skipped. By doing so, we
can make it a required check while also avoiding the 5-6 minutes of
wasted worker time.
This commit also removes the activation on push-to-master, since we really
just need to check PRs. I don't expect there to be silent merge conflicts
with this check, so if it passes on a branch it should also pass on a
successful simple rebase or merge.
It would be nice if there was a way to declare success and exit early,
but GH hasn't implemented it: https://github.com/actions/runner/issues/662
Alternatively, it would be great if skipped checks could count as
fulfilling the branch protection rules, but no luck there.
The only alternative that uses GH's built-in paths/paths-ignore
feature would be to add a second workflow with the same job name and
the opposite path triggers and that always passes. It's not clear that
this would be any less fragile or confusing than the `git diff | grep`
and step-conditionals approach.
8e513f01a1