Support for publishing PyO3 libraries to PyPI

I mostly build libraries and so have not felt much of a need to distribute pre-built binaries so far. However, one place I have noticed that binaries are more or less needed is several Python bindings I've built in tandem with Rust libraries. I think this pattern is increasingly popular (thanks to how awesome PyO3 is). Would you consider support for this in scope of cargo-dist?

For example, I recently wanted to publish a new version of the Python bindings for [instant-distance](https://github.com/InstantDomain/instant-distance/blob/main/.github/workflows/publish.yml). Unfortunately the Windows setup has somehow bitrotted (so the latest version has no Windows binaries up for now), and the newest Python release was not yet included.

Start by reading the issue's instant-distance example at .github/workflows/publish.yml and examining how cargo-dist handles release workflows. Determine the requirements for publishing PyO3 libraries to PyPI, including Windows binaries and new Python releases; done means the workflow can reliably publish those artifacts.

Written by the indexing model from the issue text.