Set up PyPI Trusted Publishing with Github Actions (or add PyPI maintainers)

[eriknw]

@jarrodmillman or @stefanv, we would like to set up a Github Action for releasing spatch using PyPI's Trusted Publishing. Since you two are the only maintainers of spatch on PyPI right now, you will need to either:

1. set up Trusted Publishing for us (the workflow name can be release.yml), or
2. add @eriknw (me), @seberg, and/or @Schefflera-Arboricola as maintainers on PyPI so one of us can set it up (PyPI handles are the same as Github handles for me and @Schefflera-Arboricola, but I don't know @seberg's PyPI handle, so if you want added, let us know).

It is also best practice to create an environment named pypi for a Github repo (available under "Settings->Environment") to use for Trusted Publishing. We are unable to do this with our current role of "maintainer" for this repo, but one of you should be able to set it up pretty easily if you want.

Thanks!