mv-python

> You added an import setuptools to a source file that dind't contain it or import distutils before. The source file in question is imported, for example, when cython is...

> AFAIK, the only user visible interfaces that require distutils are cythonize and pyximport I was thinking about that see comment about but there is also `cython.inline` and Jupiter notebook...

> and stop using distutils altogether. Not sure if we don't break someone who is not using setuptools and has python < 3.12. To be backward compatible, I am afraid...

Rebased from master containing refactor of Cache code. Now PR is clean and ready for review.

> Maybe add a wrapper function run_cached_pipeline? implemented.

Now when I am looking at it again, I agree with @da-woods and @scoder. I think closing #1981 will eventually close this issue.

> The "version specific" problem is a big complication What is a big complication. Is it a problem to release with Cython also Shadow file in separate package? I think...

> So it needs to be kept fairly strictly backwards compatible. Just several thoughts: 1. Cython_Shadow should follow common compatibility as any other library so I think is nothing unusual....

> but could do something more or less smart in Python. I think what user is going to expect more and more is to be compatible/conforming with typing system of...

@tolmanam I have fixed unittests. Could you please rebase from stable? Now it should be fine.