py-cython: updated to 0.29.30

0.29.30 (2022-05-16)
====================

Bugs fixed
----------
* The GIL handling changes in 0.29.29 introduced a regression where
  objects could be deallocated without holding the GIL.

0.29.29 (2022-05-16)
====================

Features added
--------------
* Avoid acquiring the GIL at the end of nogil functions.
  This change was backported in order to avoid generating wrong C code
  that would trigger C compiler warnings with tracing support enabled.

Bugs fixed
----------
* Function definitions in ``finally:`` clauses were not correctly generated.
* A case where C-API functions could be called with a live exception set was fixed.
* Pickles can now be exchanged again with those generated from Cython 3.0 modules.
* Cython now correctly generates Python methods for both the provided regular and
  reversed special numeric methods of extension types.
* Calling unbound extension type methods without arguments could raise an
  ``IndexError`` instead of a ``TypeError``.
* Calling unbound ``.__contains__()`` super class methods on some builtin base
  types could trigger an infinite recursion.
* The C union type in pure Python mode mishandled some field names.
* Allow users to overwrite the C macro ``_USE_MATH_DEFINES``.
* Improved compatibility with CPython 3.10/11.
* Docstrings of descriptors are now provided in PyPy 7.3.9.


(adam)