qa/tasks/cram: use suite_repo repository for all cram jobs

qa/tasks/cram: use suite_repo repository for all cram jobs

Currently git.ceph.com is hardcoded for all cram jobs.  Testing
modifications is a pain: one needs to push to either ceph/ceph.git or
ceph/ceph-ci.git (depending on where the ceph branch is at, triggering
unnecessary builds in the latter case) and wait for the mirror to sync.
Runs scheduled against branches in developer's forks fail.

Move away from git.ceph.com to allow mixing branches and repositories,
similar to workunits.

Fixes: https://tracker.ceph.com/issues/27211
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>