crimson/osd/osd_operations/snaptrim_event: Handle missing clone obc

crimson/osd/osd_operations/snaptrim_event: Handle missing clone obc

The case where resolve_oid is not able to return the clone oid (in order
to load the clone obc) should result in an SNAPTRIM_ERROR and stop the loop
iteration. Without taking this case into account an infinite loop of snap
trim events will be created.
The ENOENT error is delegated upwards to be handled by PG::on_active_actmap().

Fixes: https://tracker.ceph.com/issues/59231
Signed-off-by: Matan Breizman <mbreizma@redhat.com>