gh-87135: threading.Lock: Raise rather than hang on Python finalization

[encukou]

After Python finalization gets to the point where no other thread can attach thread state, attempting to acquire a Python lock will hang.
Raise PythonFinalizationError instead of hanging.

@colesbury, does this look maintainable (and correct) to you?

• Issue: pthread_exit & PyThread_exit_thread from PyEval_RestoreThread etc. are harmful #87135

[colesbury]

I think this approach makes sense. A comment about the flags below

[vstinner]

Tests / Windows (free-threading) / Build and test (arm64) (pull_request)
Tests / Windows (free-threading) / Build and test (x64) (pull_request)

There is a suspicious error when running test.test_multiprocessing_spawn.test_processes:

Assertion failed: !PyErr_Occurred(), file D:\a\cpython\cpython\Python\specialize.c, line 740 Fatal Python error: Aborted <Cannot show all threads while the GIL is disabled> Stack (most recent call first): File "D:\a\cpython\cpython\Lib\logging\__init__.py", line 891 in _removeHandlerRef Current thread's C stack trace (most recent call first): <cannot get C stack on this system> 

[vstinner]

LGTM