osd-recovery-prio: race condition fix in TEST_recovery_pool_priority

Use norecover to pause recovery ops while inspecting reservation
state. Without it, recovery can complete before the admin-socket
dump is captured, causing intermittent test failures

Fixes: https://tracker.ceph.com/issues/77113
Signed-off-by: Nitzan Mordechai <nmordech@ibm.com>