Add support for python 3.13

[MarkDaoust]

Description of the bug:

Python 3.13 is launching soon, ensure any new releases are compatible.

Actual vs expected behavior:

We don't have any tests for 3.13. Add a test action for 3.13

Any other information you'd like to share?

No response

[Realiserad]

Any updates on this? Python 3.13 has been out for a month now and is the Python version used in e.g. Fedora 41.

[JoshuaC215]

3.13 support is broken for this package due to https://github.com/google-gemini/generative-ai-python/issues/585 (closed but not fixed)

See: https://github.com/googleapis/proto-plus-python/issues/490

[parthea]

cc @MarkDaoust