[3.13] gh-128772: Fix pydoc for methods with __module__ is None (GH-129177) (GH-129653)

(cherry picked from commit 979d766209)

Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>

Lib/test/test_pydoc/module_none.py

@@ -0,0 +1,8 @@
+def func():
+    pass
+func.__module__ = None
+
+class A:
+    def method(self):
+        pass
+    method.__module__ = None