Implementing PEP 609: PyPA Governance

At this point I’ve added everyone that I’m able to and everyone that has reached out to me. Happy to add anyone that is missing but at this point there isn’t much else I can do to get the stragglers.

I think we can check the “Get the pypa-committers mailing list up-to-date (and a way to maintain this?)” checkbox here and I’ll be bringing PyPA as a PSF Fiscal Sponsoree forward for a vote shortly.