Moves one of the patchcheck checks to pre-commit.

1.

patchcheck's normalize_docs_whitespace runs on files where fn.startswith('Doc') and fn.endswith(('.rst', '.inc')

pre-commit's trailing-whitespace is already running on c, python and rst in the whole codebase.

So this widens the check to cover inc files in the whole codebase, not just in Doc. I think this is a good thing.

2.

patchcheck substitutes matches of re.compile(br'\s+(\r?\n)$') with br'\1. That is, it strips multiple trailing \r and \n characters.

pre-commit's trailing-whitespace trims all trailing whitespace by default (docs). This also widens the check, I think this is a good thing.

3.

Remove docs_modified(doc_files) from patchcheck, it merely printed out whether any docs files were modified. I don't think it's useful now patcheck does no docs checking, and I'd like to eventually remove patchcheck.

4.

Some people might be still running make patchcheck? If so, to maintain some kind of parity, I've added steps to install and run pre-commit as part of the Makefile command.

We're doing a similar thing in the PEPs repo:

https://github.com/python/peps/blob/a159a9ac58ca73dc1da0b626b6df77807af455d0/Makefile#L62-L77

(And Pillow: https://github.com/python-pillow/Pillow/blob/main/Makefile)

Does this seem useful, or better to leave it out?

5.

Finally, some cleanup of patchcheck.py: whitespace, f-strings, consistent pluralised outputs, fix typo.

• Issue: Move Azure Pipelines CI to GitHub Actions #109408