py-cython: updated to 0.29.22

0.29.22 (2021-02-20)
====================

Features added
--------------
* Some declarations were added to the provided pxd includes.

Bugs fixed
----------
* A crash when calling certain functions in Py3.9 and later was resolved.

* ``const`` memory views of structs failed to compile.

* ``const`` template declarations could not be nested.

* The declarations in the ``cpython.pycapsule`` module were missing their
  ``const`` modifiers and generated incorrect C code.

* Casts to memory views failed for fused dtypes.

* ``repr()`` was assumed to return ``str`` instead of ``unicode`` with ``language_level=3``.

* Calling ``cpdef`` functions from cimported modules crashed the compiler.

* Cython no longer validates the ABI size of the NumPy classes it compiled against.
  See the discussion in https://github.com/numpy/numpy/pull/432

* A C compiler warning about enum value casting was resolved in GCC.

* Coverage reporting in the annotated HTML file failed in Py3.9.

* The embedding code now reports Python errors as exit status.

* Long type declarations could lead to (harmless) random changes in the
  C file when used in auto-generated Python wrappers or pickled classes.

Other changes
-------------
* Variables defined as ``cpdef`` now generate a warning since this
  is currently useless and thus does not do what users would expect.

(adam)