Remove global toFree list from Python interop module

[jabraham17]

Removes the global toFree list from the Python interop module, which was a workaround for mishandling Python decrefs.

Resolves future work from #26353

• Tested start_test test/library/packages/Python

[Reviewed by @]

[DanilaFe]

It's difficult to fully verify the decref discipline by reading a diff as I am, but assuming all your memleaks tests pass and you can invoke that dreaded NumPy tensor fn, I think this is good to go.