Automatically label release-affecting changes

[mx-psi]

All changes can affect a release, but some changes are more likely to do so. In particular, changes that modify certain files (release workflows, Makefiles...) are likely to affect the release in unexpected ways. To help the release manager identify said changes, we can automatically add a label to changes that affect a release and label them. This can then help the release manager identify which changes may have broken the release.