Check if there is a changelog entry

[davisagli]

It would be nice to have an automated check that a pull request includes a new changelog entry.

I keep being surprised that this isn't here already.

[gforcada]

We do that with Mr.roboto so far, but indeed, having it as a standalone GHA or GitLab CI would be nice 👍

[davisagli]

Yeah, I want it for an addon that is not using mr.roboto