Cython packages need rebuild on all Python interpreter updates

Hi, It has recently come to my attention that Cython uses CPython's private API, which is unstable, see [1]. From https://docs.python.org/3/c-api/stable.html:

Names prefixed by an underscore, such as _Py_InternalState, are private API that can change without notice even in patch releases.

Meaning that packages that ship Cython modules are dependent on the interpreter version, and need to be rebuilt on all python release updates, including patch releases. [1] https://github.com/cython/cython/issues/5275 Cheers, Filipe Laíns