Added positional-only marker in lookup_special definition (#8)

Co-authored-by: JoBe <165585785+JoBeGaming@users.noreply.github.com>

Author: tanloong

Lib/types.py

@@ -82,7 +82,7 @@ def _m(self): pass
     def enclose_lookup_special():
         _sentinel = object()
 
-        def lookup_special(object, name, default=_sentinel):
+        def lookup_special(object, name, default=_sentinel, /):
             """Lookup method name `name` on `object` skipping the instance
             dictionary.