python 3.10 vs cmake python module logic

[cyrush]

python 3.10 packaging changed and the upshot that the changes are undermining our cmake logic to create mixed python script and compiled python modules.

specifically:

It resurrected the creation of zip-based eggs files for our pure python lib.
Since the py files are squirreled away into a zip file, that means that the python scripts don't land next to the shared libs they are referencing.

I have no clue why eggs are back as zombies b/c eggs are deprecated format.

It turns out we can use:

--old-and-unmanageable

To to avoid the eggs, which I note we have been otherwise already been avoiding for several years.

Need to go back and study newspeak to understand why --old-and-unmanageable helps us avoid deprecated behavior.

[cyrush]

--old-and-unmanageable only seems to work in some cases.

I move from distuils to setuptools and pip install as suggested.

That said, turns out that I had to re-enable egg creation for the proper legacy path to work.

So eggs are back.

[cyrush]

resolved in #1232