qa: Disable OSD benchmark from running for tests.

qa: Disable OSD benchmark from running for tests.

Disable OSD bench from benchmarking the OSDs for teuthology tests. This is to
help prevent a cluster warning pertaining to the IOPS value not lying within
a typical threshold range from being raised.

The tests can rely on the built-in static values as defined by
osd_mclock_max_capacity_iops_[ssd|hdd] which should be good enough.

Fixes: https://tracker.ceph.com/issues/74501
Signed-off-by: Sridhar Seshasayee <sseshasa@redhat.com>
(cherry picked from commit cf04790bede6be13cc27dcdf50fe19a953860321)

 Conflicts:
       qa/config/rados.yaml
- Removed a non-existing option under mon overrides