selftests/landlock: Add tests to check unknown rule's access rights

Add two tests to make sure that we cannot add a rule with access
rights that are unknown:
* fs: layout0.rule_with_unknown_access
* net: mini.rule_with_unknown_access

Rename unknown_access_rights tests to ruleset_with_unknown_access .

Cc: Konstantin Meskhidze <konstantin.meskhidze@huawei.com>
Reviewed-by: Günther Noack <gnoack@google.com>
Link: https://lore.kernel.org/r/20231130093616.67340-2-mic@digikod.net


Signed-off-by: Mickaël Salaün <mic@digikod.net>