Message 354677 - Python tracker

> Kyle Stanley proposed a fix: PR 16293.

Note that I'm not confident about the fix I proposed in GH-16293, it was more of an idea to fix the intermittent failures more than anything. It definitely needs review from someone knowledgeable about sub-interpreters and the PyInterpreterState API. This isn't an area that I'm experienced in, but I am interested in it.