Used addCleanup() in tests where appropriate.

tests/i18n/patterns/tests.py

@@ -52,10 +52,8 @@ class URLTestCaseBase(SimpleTestCase):
     def setUp(self):
         # Make sure the cache is empty before we are doing our tests.
         clear_url_caches()
-
-    def tearDown(self):
         # Make sure we will leave an empty cache for other testcases.
-        clear_url_caches()
+        self.addCleanup(clear_url_caches)
 
 
 class URLPrefixTests(URLTestCaseBase):

tests/i18n/tests.py

@@ -1756,10 +1756,7 @@ class ResolutionOrderI18NTests(SimpleTestCase):
     def setUp(self):
         super().setUp()
         activate("de")
-
-    def tearDown(self):
-        deactivate()
-        super().tearDown()
+        self.addCleanup(deactivate)
 
     def assertGettext(self, msgid, msgstr):
         result = gettext(msgid)