[3.9] bpo-46424: [typing] cover Annotation[arg] invalid usage in tests (GH-30663) (GH-30692)

(cherry picked from commit 3239829)


Co-authored-by: Nikita Sobolev <mail@sobolevn.me>

Author: miss-islington

Lib/test/test_typing.py

@@ -4243,6 +4243,10 @@ def test_cannot_check_subclass(self):
         with self.assertRaises(TypeError):
             issubclass(int, Annotated[int, "positive"])
 
+    def test_too_few_type_args(self):
+        with self.assertRaisesRegex(TypeError, 'at least two arguments'):
+            Annotated[int]
+
     def test_pickle(self):
         samples = [typing.Any, typing.Union[int, str],
                    typing.Optional[str], Tuple[int, ...],