Fix from-source and Python 3.12 build by removing hard-coded version (#922)

[dhdaines]

Switch to using setuptools-git-versioning instead of a hardcoding the version at release time with a default version string that was not friendly to PEP440, Python 3.12, or building from git source.

Checklist

• [ x ] I have read CONTRIBUTING.md.
• [ x ] I have added a concise human-readable description of the change to CHANGELOG.md.
• [ x ] I have tested that this fix is effective or that this feature works.
• [ x ] I have added docstrings to newly created methods and classes.
• [ x ] I have updated the README.md and the readthedocs documentation. Or verified that this is not necessary.

[dhdaines]

not sure why it doesn't get mentioned there but this fixes #922

[pietermarsman]

This is looking great. I've rewritten the CHANGELOG.md a bit, and merged master into this branch.

Can you look at the failing tests? If that is fixed it is ready to be merged.

[pietermarsman]

@dhdaines I've fixed the tests. Perhaps you can give it another look next week. I'm planning to merge it next week.

[dhdaines]

@dhdaines I've fixed the tests. Perhaps you can give it another look next week. I'm planning to merge it next week.

Hi! Sorry for the late reply... I was on top of a mountain for a few days. Seems to all work quite well for me on Python 3.12.

As far as I can tell the release workflow should work in the same way but I wouldn't be able to test that :)

[pietermarsman]

No worries. I haven't responded in quite a while, and I was not on a mountain 😄

The work you put in here is much appreciated!