Support GIL-less Python 3.13

[sentrivana]

There's an experimental build of Python 3.13 with the GIL disabled. We should investigate how the SDK behaves on it, and ideally also run the tests against it in CI.

[szokeasaurusrex]

cool!

[antonpirker]

Yes, we could run our test suite against nogil Python.
Here are also some more information that are helpful: https://drew.silcock.dev/blog/everything-you-need-to-know-about-python-3-13/