fixed test to match new error message

Author: randolf-scholz

Lib/test/test_patma.py

@@ -3449,7 +3449,7 @@ def test_class_pattern_not_type(self):
     def test_class_or_union_not_specialform(self):
         from typing import Literal
         name = type(Literal).__name__
-        msg = rf"called match pattern must be a class or typing.Union of classes \(got {name}\)"
+        msg = rf"called match pattern must be a class or a union of classes \(got {name}\)"
         w = None
         with self.assertRaisesRegex(TypeError, msg):
             match 1: