Extend test matrix up to 3.12

[foarsitter]

In the same vein as https://github.com/dropbox/dropbox-sdk-python/pull/481, this PR updates the test matrix & classifiers up to the most recent 3.12.

Checklist

General Contributing

• [X] Have you read the Code of Conduct and signed the CLA?

Is This a Code Change?

• [X] Non-code related change (markdown/git settings etc)
• [ ] SDK Code Change
• [ ] Example/Test Code Change

Validation

• [x] Does tox pass?
• [x] Do the tests pass?

[CLAassistant]

All committers have signed the CLA.

[greg-db]

Thanks for putting this together! I'll ask the team to review this.

[hugovk]

Does this fail on 3.12 with https://github.com/dropbox/dropbox-sdk-python/issues/483?

[foarsitter]

@hugovk It did not fail on 3.12 for the CI: https://github.com/foarsitter/dropbox-sdk-python/actions/runs/6707504248

[sarahboyce]

@hugovk It did not fail on 3.12 for the CI: https://github.com/foarsitter/dropbox-sdk-python/actions/runs/6707504248

@foarsitter this is because requirements.txt also includes some requirements for development including sphinx which installs setuptools. Ref raw logs of the action:

2023-10-31T13:53:47.3735410Z Collecting setuptools (from babel>=2.9->sphinx->-r requirements.txt (line 9))

I think the packages in the requirements.txt under # Other dependencies for development should be in their own requirements file and not installed in the CI (sphinx for example is explicitly installed in the docs ci step anyway).

If you remove sphinx from requirements.txt, I think that the Python 3.12 ci will fail. I believe https://github.com/dropbox/dropbox-sdk-python/pull/484#discussion_r1398181635 is needed. I can't activate a virtual environment here on Python 3.12 without this change.

[foarsitter]

@sarahboyce do you think it is sufficient to not pin setuptools and let pip decide? Thanks for pointing out that sphinx was installing setuptools in this case.

I added an issue to move to pyproject.toml: https://github.com/dropbox/dropbox-sdk-python/issues/487