Use setup-python instead of setup-micromamba for pre-commit CI

[RMeli]

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📚 Documentation preview 📚: https://mdanalysisuserguide--388.org.readthedocs.build/en/388/

[RMeli]

We had a failure in #387. Trying to see if using setup-python works.

Others encountered the same issue https://github.com/pre-commit/action/issues/214, https://github.com/pre-commit/action/issues/213, https://github.com/pre-commit/action/issues/210. Honestly, the replies from the maintainer on these issues makes me want to steer clear of the pre-commit GitHub action.

Additionally:

this action is in maintenance-only mode and will not be accepting new features. generally you want to use pre-commit.ci which is faster and has more features.

Maybe we should consider moving to pre-commit.ci? @jandom?

[RMeli]

I could not find much information on why this is happening now. But it seems that the action is only in maintenance mode, and the maintainer is very quick at closing issues. In the ones outlining this problem (linked above, links were wrong and I just updated them), replies are of the sort

you are the third or fourth person to not search before creating an issue for this specific thing. please do better!

or

skill issue imo. it is in the readme you just didn't follow it or read the output of your own job

So not much information there. The README uses the setup-python action to setup Python for pre-commit, so that's what I went for and it seems to work as expected.

[orbeckst]

The maintainer comments on the pre-commit issues are not particularly welcoming. I don't quite know what would be better for a "maintenance-only" project: no response at all or harsh responses + shutting down issues. 🤷