Improve the release process to enable trusted publishing

[pradyunsg]

/cc @sethmlarson who I briefly mentioned this to at PyCon US 2024

The current process is documented at
https://pip.pypa.io/en/stable/development/release-process/

The idea here would be to automate the end-to-end process to happen on a publicly auditable location and through trusted publishers via GHA to publish to PyPI.

[sethmlarson]

Woo! 🚀 Sounds good to me :)

[sbidoul]

Let's do this? #13048