Removal of extraneous parenthesis in tests (#33670)

* Removal of extraneous parenthesis

* Process review suggestions

* Apply suggestions from code review

Co-authored-by: Martin Hjelmare <marhje52@gmail.com>

tests/components/folder/test_sensor.py

@@ -28,7 +28,7 @@ class TestFolderSensor(unittest.TestCase):
         self.hass = get_test_home_assistant()
         if not os.path.isdir(TEST_DIR):
             os.mkdir(TEST_DIR)
-        self.hass.config.whitelist_external_dirs = set((TEST_DIR))
+        self.hass.config.whitelist_external_dirs = {TEST_DIR}
 
     def teardown_method(self, method):
         """Stop everything that was started."""