Fixed test from refs #23913 when running tests in reverse.

tests/template_tests/syntax_tests/test_if.py

@@ -2,6 +2,7 @@ import warnings
 
 from django.template import TemplateSyntaxError
 from django.test import ignore_warnings, SimpleTestCase
+from django.test.utils import reset_warning_registry
 from django.utils.deprecation import RemovedInDjango20Warning
 
 from ..utils import setup, TestObj
@@ -528,6 +529,7 @@ class IfTagTests(SimpleTestCase):
     @setup({'if-tag-eq-deprecated': '{% if foo = bar %}yes{% else %}no{% endif %}'},
         test_once=True)
     def test_if_tag_eq_deprecated(self):
+        reset_warning_registry()
         with warnings.catch_warnings(record=True) as warns:
             warnings.simplefilter('always')
             output = self.engine.render_to_string('if-tag-eq-deprecated')