fix: #8034 chown parse trailing colon as implicit group-is-user

[MarcusGrass]

fixes #8034

Resurrects #8156

I'll have another stab at the CI issues

[github-actions]

GNU testsuite comparison:

Skip an intermittent issue tests/date/resolution (fails in this run but passes in the 'main' branch)
Skip an intermittent issue tests/misc/tty-eof (fails in this run but passes in the 'main' branch)
Skipping an intermittent issue tests/cut/bounded-memory (passes in this run but fails in the 'main' branch)
Skipping an intermittent issue tests/pr/bounded-memory (passes in this run but fails in the 'main' branch)
Skipping an intermittent issue tests/tail/tail-n0f (passes in this run but fails in the 'main' branch)
Congrats! The gnu test tests/cut/cut-huge-range is now passing!

[MarcusGrass]

I'd consider the branch resurrected, things have changed in the underlying system and the current errors are just test-procedure that needs to be fixed up, something with the CI on macos, and a test-condition that doesn't hold for OpenBSD

[MarcusGrass]

I don't like this openbsd hack but it seems that the directory has a sticky wheel group on it, not sure of easy ways to solve that at the moment. Improvement suggestions welcome.
Last one is an issue on the mac-runner where it runs as the user runner but no group exists for that user so setting runner:runner fails because of it