This is a task to:
- try if the existing puppet classes for gitlab-runners "just work" on bullseye like they do in buster
- import gitlab-runner package from external repo into Wikimedia apt repo
- see what (packages) might be missing or what changes are needed to upgrade
- eventually upgrade all the existing runners to bullseye
- upgrade Trusted Runners to bullseye
break-out from ticket T297411#7567146