Adds the maintain-heart-rate to quarantine. (#10922)

The test occasionally fails, moving it to quarantine for now.

tests/jobs/test_local_task_job.py

@@ -255,6 +255,7 @@ class TestLocalTaskJob(unittest.TestCase):
 
         session.close()
 
+    @pytest.mark.quarantined
     def test_localtaskjob_maintain_heart_rate(self):
         dagbag = DagBag(
             dag_folder=TEST_DAG_FOLDER,