Refs #26666 -- Added ALLOWED_HOSTS validation when running tests.

Also used ALLOWED_HOSTS to check for external hosts in assertRedirects().

tests/cache/tests.py

@@ -1393,6 +1393,7 @@ class DefaultNonExpiringCacheKeyTests(SimpleTestCase):
         },
     },
     USE_I18N=False,
+    ALLOWED_HOSTS=['.example.com'],
 )
 class CacheUtils(SimpleTestCase):
     """TestCase for django.utils.cache functions."""