Use issue_warning helper to get best stacklevel (sometimes it could point to ResourceManager.resource_filename not user code)

Author: brondsem

pkg_resources/__init__.py

@@ -1661,10 +1661,9 @@ def _validate_resource_path(path):
 
         # for compatibility, warn; in future
         # raise ValueError(msg)
-        warnings.warn(
+        issue_warning(
             msg[:-1] + " and will raise exceptions in a future release.",
             DeprecationWarning,
-            stacklevel=4,
         )
 
     def _get(self, path):