testmap: Drop cockpit-composer RHEL 10

The package was removed from RHEL 10.

Author: martinpitt

lib/testmap.py

@@ -168,9 +168,7 @@ def contexts(image: str, *scenarios: Iterable[str], repo: str | None = None) ->
             'fedora-40',
             'fedora-40/firefox',
             'centos-9-stream',
-            'centos-10',
             'rhel-9-6',
-            'rhel-10-0',
         ],
         '_manual': [
             'fedora-rawhide',