qa/workunits/cephadm: align test_cephadm.sh with new cephadm version

qa/workunits/cephadm: align test_cephadm.sh with new cephadm version

The `cephadm version` command no longer bases the output on the
container images, rather it uses a special python file added to the
zipapp during the build to report on the version of cephadm (the
binary).

The other option was to preserve this behavior and add a new version
command or make it behave differently depending on what options were
provided. I discussed the options with AMK in person and we decided that
changing the tests was preferable.

Signed-off-by: John Mulligan <jmulligan@redhat.com>
(cherry picked from commit bd59b8091929ff067fabd4c8ca7ad86b3723aa0f)