doc: mention encryption is not supported for static PVC

Closes: #6209
Signed-off-by: Praveen M <m.praveen@ibm.com>

Author: iPraveenParihar

docs/static-pvc.md

@@ -22,7 +22,7 @@ existing RBD image or CephFS volume.
 > [!warning]
 > static PVC can be created, deleted, mounted and unmounted but
 currently ceph-csi doesn't support other operations like snapshot,clone,
-resize, etc for static PVC
+resize, encryption etc for static PVC
 
 ## RBD static PVC