Fix tests on PyPy3.11+ (#756)

src/test_typing_extensions.py

diff --git a/src/test_typing_extensions.py b/src/test_typing_extensions.py
index 54b65f4..69aeb39 100644
--- a/src/test_typing_extensions.py
+++ b/src/test_typing_extensions.py
@@ -7443,7 +7443,7 @@
 
     def test_same_as_typing_NamedTuple(self):
         self.assertEqual(
-            set(dir(NamedTuple)) - {"__text_signature__"},
+            set(dir(NamedTuple)),
             set(dir(typing.NamedTuple))
         )
         self.assertIs(type(NamedTuple), type(typing.NamedTuple))