Once the package is ready to release, use git tag to tag the
release:
git tag -m <version> <version>
e.g:
git tag -m v0.1 v0.1
You can also include the -s flag to sign the tag if you have
PGP keys set up. Then, push the tag to GitHub, e.g.:
git push upstream v0.1
and the build should happen automatically on GitHub Actions. You can follow the progress of the build here:
https://github.com/astropy/astropy-healpix/actions/workflows/publish.yml
If there are any failures, you can always delete the tag, fix the issues, tag the release again, and push the tag to GitHub.
See the OpenAstronomy GitHub Actions Workflows for more details about the GitHub Actions set-up.