cython: update to 3.2.4

[androidnisse]

Summary

Features added

In preparation of Cython 3.3, a new decorator @collection_type(tname) can be used to advertise an extension type as being a 'sequence' or 'mapping'. This currently only has the effect of setting the Py_TPFLAGS_SEQUENCE flag on the type or not, but is provided for convenience to allow using the new decorator already in Cython 3.2 code.

Several C++ exception declarations were added to libcpp.exceptions.

Bugs fixed

Pseudo-literal default values of function arguments like arg=str() could generate invalid C code when internally converted into a real literal.

The pickle serialisation of extension types using the auto_pickle feature was larger than necessary since 3.2.0 for types without Python object attributes. It is now back to the state before 3.2.0 again.

Constants are now only made immortal on freethreading Python if they are not shared.

PyDict_SetDefaultRef() is now used when available to avoid temporary borrowed references.

Test Plan

• Ran some test code.

Checklist

• Package was built and tested against unstable
• This change could gainfully be listed in the weekly sync notes once merged