ci: support development releases of Python

[henryiii]

Description

Suggested changelog entry:

* Test python-3.11 on PRs with the ``python dev`` label.
* Support PyPy 7.3.7 and the PyPy3.8 beta.

[Skylion007]

@henryiii I think the crash might be related to calling the CPython APIs in get_type_override when being dispatched from a PURE_OVERRIDE call, specifically here:

pybind11/tests/test_factory_constructors.cpp

Line 123 in 6abf2ba

int get() override { PYBIND11_OVERRIDE(int, TestFactory6, get, /*no args*/); }

There is something about that edge case that is causing the segfault and why the other tests in pass.

[Skylion007]

@henryiii @rwgk It's not the best fix, but all tests pass for Python 3.11. We really need to open an issue about the fact that the new frame struct API should be public or at least have some getter for covarnames.

[henryiii]

Could you do that? You've looked into it the most.

[henryiii]

If you want, we could just disable the two failing tests on PyPy and move forward with PyPy testing. The garbage collector one doesn't clean up, even on 3.7, and the hook one doesn't work for mysterious reasons (I can't make a MWE, it seems to work in MWE form).

[rwgk]

Looks great, thanks!

[henryiii]

I don't think this will trigger for workflow dispatch. And I wanted it to run weekly. Can do in a followup PR.