[IMP] web: add stacklevel to DeprecationWarning

bcf665a introduced this deprecation warning without a stacklevel
argument. Adding it makes the error highlighted precisely where the
deprecated import occurred.

closes odoo#92420

X-original-commit: 9c01ab0
Signed-off-by: Julien Castiaux <juc@odoo.com>
Signed-off-by: Paul Morelle <pmo@odoo.com>

addons/web/controllers/main.py

@@ -49,7 +49,7 @@ def __getattr__(attr):
 
     @lazy
     def only_one_warn():
-        warnings.warn(f"{__name__!r} has been split over multiple files, you'll find {attr!r} at {module.__name__!r}", DeprecationWarning)
+        warnings.warn(f"{__name__!r} has been split over multiple files, you'll find {attr!r} at {module.__name__!r}", DeprecationWarning, stacklevel=4)
         return getattr(module, attr)
 
     return only_one_warn