* Split the workflow out into a reusable workflow.
* Call the release PPA workflow only on GitHub release publications.
* Call the staging PPA workflow on all GitHub release & prerelease publications.
* Clean up comments, and make them a bit more consistent.
* Add autoincrement logic to the PPA version number when the version we're building already exists on the target PPA.
* Build Lunar and Kinetic packages on Jammy since GitHub only has LTS Ubuntu runners.
