Changes for python 3.12

[cdce8p]

• Replace PyUnicode_GET_SIZE with PyUnicode_GET_LENGTH for Python >=3.3
  https://docs.python.org/3/c-api/unicode.html#c.PyUnicode_GET_SIZE
• Use datetime.fromtimestamp instead of datetime.utcfromtimestamp in the docs
  https://docs.python.org/3.12/library/datetime.html#datetime.datetime.utcfromtimestamp
• Update cibuildwheel to 2.16.2 to build wheels for 3.12
  https://cibuildwheel.readthedocs.io/en/stable/changelog/#v2162

[cdce8p]

@brandon-rhodes Not sure if you've seen it. This would make the library ready for 3.12, the first release candidate is scheduled for tomorrow already.

[brandon-rhodes]

Yes, I did see it — but have been a bit busy and, obviously, haven't responded yet. I'll try to schedule some time to work on PyEphem before the 3.12 October release, though!

[cdce8p]

I saw the failed workflow for macos-10.15. That's likely because the runner image name changed to macos-12 / macos-latest. I've updated it, the other images which also were getting old, and the basic actions to their newest releases.

https://docs.github.com/en/actions/using-github-hosted-runners/about-github-hosted-runners/about-github-hosted-runners#supported-runners-and-hardware-resources
https://github.com/brandon-rhodes/pyephem/actions/runs/6399268653/job/17374304136

[brandon-rhodes]

I saw the failed workflow for macos-10.15. …

Thank you, I hadn't known whether it was a transient problem stalling Mac builds, or something more serious. Hopefully the builds will succeed this time!

[cdce8p]

Hopefully the builds will succeed this time!

Seem like they are all good 🎉