gh-99518: Fix escape symbol in `test_enum` (#99519)

diff --git a/Lib/test/test_enum.py b/Lib/test/test_enum.py
index fb3d5ad970fba5a628bf17e25f3d4ca4c75f5313..b6082cf02b18d70361560ff01100f8763d756660 100644 (file)
--- a/Lib/test/test_enum.py
+++ b/Lib/test/test_enum.py
@@ -1478,7 +1478,7 @@ class TestSpecial(unittest.TestCase):
             class EvenMoreColor(Color, IntEnum):
                 chartruese = 7
         #
-        with self.assertRaisesRegex(ValueError, "\(.Foo., \(.pink., .black.\)\) is not a valid .*Color"):
+        with self.assertRaisesRegex(ValueError, r"\(.Foo., \(.pink., .black.\)\) is not a valid .*Color"):
             Color('Foo', ('pink', 'black'))
 
     def test_exclude_methods(self):