use forwards and backwards compatible annotation check

Author: maxfischer2781

unittests/test_functools_lru.py

@@ -2,6 +2,7 @@
 import sys
 
 import pytest
+from typing_extensions import get_annotations, Format
 
 import asyncstdlib as a
 
@@ -175,5 +176,5 @@ async def other_method(self):
             if name != "method":
                 continue
             # test direct and literal annotation styles
-            assert Bar.method.__annotations__["int_arg"] in {int, "int"}
-            assert Bar().method.__annotations__["int_arg"] in {int, "int"}
+            assert get_annotations(Bar.method, format=Format.STRING)['int_arg'] == "int"
+            assert get_annotations(Bar().method, format=Format.STRING)['int_arg'] == "int"