Add stacklevel=2 to make calling code clear

Author: hugovk

setuptools/config/__init__.py

@@ -25,7 +25,7 @@ def _wrapper(*args, **kwargs):
         to access a backward compatible API, but this module is provisional
         and might be removed in the future.
         """
-        warnings.warn(dedent(msg), SetuptoolsDeprecationWarning)
+        warnings.warn(dedent(msg), SetuptoolsDeprecationWarning, stacklevel=2)
         return fn(*args, **kwargs)
 
     return cast(Fn, _wrapper)