Use TestCase.addCleanup (#36560)

tests/components/efergy/test_sensor.py

@@ -75,8 +75,9 @@ class TestEfergySensor(unittest.TestCase):
         """Initialize values for this test case class."""
         self.hass = get_test_home_assistant()
         self.config = ONE_SENSOR_CONFIG
+        self.addCleanup(self.tear_down_cleanup)
 
-    def tearDown(self):  # pylint: disable=invalid-name
+    def tear_down_cleanup(self):
         """Stop everything that was started."""
         self.hass.stop()