types.CoroutineType.cr_frame may be None on 3.12+ (#14802)

Author: ashm-dev

stdlib/types.pyi

@@ -462,8 +462,13 @@ class CoroutineType(Coroutine[_YieldT_co, _SendT_nd_contra, _ReturnT_nd_co]):
     def cr_await(self) -> Any | None: ...
     @property
     def cr_code(self) -> CodeType: ...
-    @property
-    def cr_frame(self) -> FrameType: ...
+    if sys.version_info >= (3, 12):
+        @property
+        def cr_frame(self) -> FrameType | None: ...
+    else:
+        @property
+        def cr_frame(self) -> FrameType: ...
+
     @property
     def cr_running(self) -> bool: ...
     @property