Add support for python3.12

[sirosen]

• Test on 3.12.0rc1
• Add a changelog entry for this (the phrasing is a little bit "early", since 3.12.0 hasn't released yet, but this is the changeset which adds support for everything expected in 3.12.0)
• Update test dependencies to get the latest coverage version, for 3.12.0rc1 support
• Add py312 to the tox env list
• One minor tweak in the testsuite: datetime.datetime.utcnow() is deprecated because it produces a naive timestamp. Swap it to datetime.datetime.now() which is similar, still naive, and shouldn't trip things up much or at all.

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📚 Documentation preview 📚: https://globus-sdk-python--808.org.readthedocs.build/en/808/

[sirosen]

Two issues right now:

• need to specify as 3.12.0-rc1 for the github action (annoying but fine)
• the latest versions of some transitive dependencies in mindeps dropped py3.7 (it was going to happen sooner or later)

I'll probably do a separate body of work for the mindeps issue, possibly start on dropping 3.7 ourselves, etc.
Once I sort that out, I'll rebase and fix the py312 specifier for github.

[kurtmckee]

need to specify as 3.12.0-rc1 for the github action (annoying but fine)

That is recently no longer true!

You can set allow-prereleases: true and then just specify "3.12" as the target version. If there isn't a GA release then it'll fall back to the latest prerelease version.

python-version: "3.12"
allow-prereleases: true

[kurtmckee]

It may be possible to add constraints for the dependencies that hinge on Python 3.7...? I don't recall if we have deprecation plans of our own for Python 3.7 support yet.

[sirosen]

It may be possible to add constraints for the dependencies that hinge on Python 3.7...? I don't recall if we have deprecation plans of our own for Python 3.7 support yet.

Yeah, we don't have a plan yet, but we should. I want to try to whip something up which will read our python_requires from package data and validate it... against our CI config.
Plus, use that same data source when running the freezedeps script to get a pip-compile run on the correct python.

We'll see if I commit anything -- I give myself a 50/50 shot at writing something non-disastrous.

[kurtmckee]

The pip-compile command is being run with Python 3.11.

Can it be run with Python 3.7 to resolve the Python 3.7 pinning problems? Alternatively, I cooked up a Python-by-Python requirements generator from within tox that can be used to generate the requirements files for all supported versions of Python.

[sirosen]

Yeah, I was wanting to tackle at least a py37-test-mindeps.txt generator in a separate PR. Let's treat that as "fixing our py37" build, separately, and I'll rebase off of it.
If you want to take a crack at it, feel free. Otherwise, I'll try to do something.

[kurtmckee]

I'll leave it to you to tackle the Python 3.7 compatibility.

This PR gets a big ol' 👍!

[sirosen]

I had to do a little bit of tinkering post-rebase, mostly to get the 3.12 requirements regenerated.
Now that I've sorted that out, I'm going to let CI run and merge based on the prior approval when it passes.