pyo3 (and part of the ecosystem): upgrade to 0.21.1

This drops the in-tree (but unreleased) version from 0.22.0 to 0.21.1, since the rest of the pyo3 ecosystem doesn't appear to be there yet.

pep508_rs is experiencing an package test failure, but I'm not yet quite skilled enough to understand what is going on there.

pep508 and pep440 required new packages, packaged here.

pythonize, pyo3-log, and pyproject-toml also get upgrades