Cleaning up build tools

[john-science]

What is the change?

Here I clean up our build tools in twoways:

1. Splitting our unit test Worflows into two parts:

• Older versions of Python get Ubuntu 22.04
• Newer versions of Python need Ubuntu 24.04

2. Dropping direct usage of distutils

Why is the change being made?

With this PR I was originally trying to support Python 3.12 but found that we couldn't due to our NumPy jagged array issue.

But this PR gets ARMI 99.9% ready for Python 3.12; everything except our NumPy woes.

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Checklist

• This PR has only one purpose or idea.
• Tests have been added/updated to verify any new/changed code.

• The code style follows good practices.
• The commit message(s) follow good practices.

• The release notes have been updated if necessary.
• The documentation is still up-to-date in the doc folder.
• The dependencies are still up-to-date in pyproject.toml.

[opotowsky]

Nice dep cleanup!

Do we even NEED py37/38 testing still?

I leave that up to you. I approve 🎉

[john-science]

Do we even NEED py37/38 testing still?

I don't know. That is certainly pretty borderline.

I assume support for those will drop naturally in the next year or two. Like, it'll be too hard to support 3.7 AND 3.12 for numpy or something, and we'll just drop support for numpy. Like, the moment it becomes hard to support them, we'll drop support.

But, for now, it's still easy. #shrug