Update sdks/python/apache_beam/transforms/core_test.py

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

Author: derrickaw

sdks/python/apache_beam/transforms/core_test.py

@@ -346,8 +346,7 @@ def test_optional_type_for_field(self):
         row_type.RowTypeConstraint.from_fields([('a', typing.Optional[int])]))
 
   def test_none_type_for_field_raises_error(self):
-    with self.assertRaisesRegex(TypeError,
-                                "('No types found for field %s', 'a')"):
+    with self.assertRaisesRegex(TypeError, "No types found for field a"):
       beam.Create([beam.Row(a=None), beam.Row(a=None)]).infer_output_type(None)