pypi publish for musl linux

[starpit]

I think this one should be straightforward. The .github/workflows/publish_pypi.yml already has a (commented out) section for musl. This requires figuring out the openssl parts. We already have something in place for that, too... see the openssl-vendored feature, and note how the top-level Cargo.toml uses it for cross builds. So we i think just need to wire this all up into the workflow.

e.g. PyO3/maturin-action#162 (comment)