set up pre-commit on github actions

[Mikejmnez]

The following Pull Request:

• Closes an already existing opened issue run pre-commit on PRs and have auto updates #311 requesting
  a new feature, etc.
• Tests are not needed since this is about gh actions - no change to code

[Mikejmnez]

Hmm. Two things going on:

1. tests with macOs fail with the following error:

 Error: The version '3.9' with architecture 'arm64' was not found for macOS 14.4.1.

This is being reported since yesterday in here actions/setup-python#850. It looks like the issue is due to

macos-latest now uses M1 runners (macos-14-arm64) and 3.9 and earlier aren't available there: #696 (comment)
To fix, you can use one of the options at python/peps#3763, or stick to macos-12 or macos-13 (but you get some nice speedups using M1 where available).

2. pre-commit is failing when running flake8 on a test file.

src/pydap/tests/dap_4_access/dap4_access_test.py:73:47: E226 missing whitespace around arithmetic operator

I noticed that pre-commit is running python 3.12, whereas no other action is running that version of python. It is possible the error is due to that. Indeed the issue was E226 on newer version of python.

I will investigate 1) tomorrow.

[Mikejmnez]

woohoo!
I had to remove python 3.9 from macos-latest from github actions because the runners on "macos-latest" are all M1. To run tests with python 3.9 on mac-os we'd have to define a separate runs-on: macos-13 yaml file.

[Mikejmnez]

@jgallagher59701 This is ready for review. As you can see pre-commit is now running on GH actions starting on this PR.

[jgallagher59701]

Yes, this looks ready to merge. Thanks!

[jgallagher59701]

Merge! Thanks.