https://src.fedoraproject.org/rpms/setup/c/7ced36d60b67c9e74f7951123225200597e3d2fa?branch=rawhide merged the two setup sysusers files into one and changed the name, so let's adapt the test_sysusers_defined check for those changes.
For https://github.com/systemd/systemd/pull/34876.
- We rely on setup to provide all necessary groups.