Relax a test regex to match new enum repr in Python 3.10.0a7+ (#186)

bpo-40066: Enum: adjust repr() to show only enum and member name (not value,
nor angle brackets) and str() to show only member name.
https://bugs.python.org/issue40066

test/test_pgen2.py

@@ -339,7 +339,7 @@ def test_left_recursion():
 @pytest.mark.parametrize(
     'grammar, error_match', [
         ['foo: bar | baz\nbar: NAME\nbaz: NAME\n',
-         r"foo is ambiguous.*given a PythonTokenTypes\.NAME.*bar or baz"],
+         r"foo is ambiguous.*given a (PythonTokenTypes\.)?NAME.*bar or baz"],
         ['''foo: bar | baz\nbar: 'x'\nbaz: "x"\n''',
          r"foo is ambiguous.*given a ReservedString\(x\).*bar or baz"],
         ['''foo: bar | 'x'\nbar: 'x'\n''',