Improvements

Rook v1.18.9 is a patch release limited in scope and focusing on feature additions and bug fixes to the Ceph operator.

• csi: Disable read affinity for ceph v20.2.0 to avoid corruption (#16895, @travisn)
• core: Allow skipping cephcluster reconcile via do-not-reconcile label (#16874, @OdedViner)
• helm: Merge rook-config-override ConfigMap into toolbox ceph.conf (#16862, @mheler)
• helm: Add cephclusters/finalizers permission for mgr sidecar (#16854, @grandeit)
• csi: Add fix to support multiple fs mount option (#16837, @subhamkrai)
• operator: Watch cephConfigFromSecret changes (#16786, @cyanidium)
• rgw: Support all S3 notification events in CRD validation (#16804, @arttor)
• docs: Add pool parameter for erasure code optimizations (#16789, @travisn)