Pin ansible-compat<4 until we upgrade ansible-lint

There was a regression introduced in ansible-compat v4 which stopped
ansible-lint from working. This was fixed in ansible-lint 6.16.0 but
we've pinned it for so long now that there are a lot of rule
violations to fix or mark for skipping. In the interim, pin back all
new versions of ansible-compat until someone has time to fix things
or rip out ansible-lint entirely.

Change-Id: I68e06bbfaf0b38582320f09659dfc462016eacf8

tox.ini

@@ -34,10 +34,9 @@ deps =
      # things from a later ansible that would actually fail in
      # production.
      ansible>=5,<6
-     # pin until https://github.com/ansible/ansible-lint/issues/2320 is fixed
+     # pin these two until someone has time to update all our skips to >=6.16
      ansible-lint>=6.0.0,<6.5.0
-     # avoid for https://github.com/ansible/ansible-compat/issues/258
-     ansible-compat!=4.0.1,!=4.0.2
+     ansible-compat<4
      hacking>=4.0.0,<5.0.0
      bashate>=0.2
 commands =