To create a release, create a tag. It must follow the x.y.z pattern without any prefix.
VERSION=x.y.z
git tag -s "$VERSION" -m "Release $VERSION"
git push --follow-tags
This will create a GitHub release and attach the created tarball to it.
Once that is done, the packaging is handled in the foreman-packaging repository where the spec file is maintained:
obal update foremanctl --version $VERSION
gh pr create --base rpm/develop