qa/suites/fs: pull compiled cephadm for squid branch in mds_upgrade_sequence
The approach to pull from github stopped working after quincy.
We need to use this new compiled_cephadm_branch option to pull
the binary for reef or squid unless the cephadm we want is the
one from the actual build we're testing (so basically just
pre-upgrade in upgrade tests)
Fixes: https://tracker.ceph.com/issues/66786 Signed-off-by: Adam King <adking@redhat.com>