qa/tests: drop parens from all health-code ignorelist entries

Monitor.cc logs a "Health check cleared: <CODE> (was: ...)" line
for any health check clearing mid-test, with the code bare (no
parens) -- while the "Health check failed"/"Health check failed
(unmute)" lines wrap the code in parens. Every \(CODE\) entry in
this file therefore only matches the raise/failed form and misses
the corresponding cleared form, the same gap just fixed for
POOL_FULL.

Drop the escaped parens from the remaining entries so each matches
both log forms, consistent with the bare entries already present
(OSD_ROOT_DOWN, MDS_INSUFFICIENT_STANDBY, POOL_FULL).

Non-code entries (reached quota, overall HEALTH_, slow request,
noscrub, nodeep-scrub, osds down, insufficient standby, etc.) are
unchanged.

Fixes: https://tracker.ceph.com/issues/78149
Signed-off-by: Yuri Weinstein <yweinste@redhat.com>