ci: Add pre-commit workflow

[mdeweerd]

This runs the pre-commit setup in a github workflow that will also annotate the PRs.

[larsoner]

I think inline comments are neat but I'm worried about adding a bunch of new infrastructure that we need to maintain. Ideally contributors would pre-commit install --install-hooks locally and see the errors. And if they don't do that, then click the "details" button on the failed CI.

[mdeweerd]

Seeing the annotation in context is IMHO more efficient, not just neat.
If the annotations break in the future, the related steps can just be disabled/commented/removed.

Annotations are fairly new - I think that we'll see more features coming in the github ui. I suppose that at some point in time an annotation can be turned into an issue in the UI - something that I do not expect in the textual report/details view.

[mdeweerd]

1 year old, so considered as "not accepted".