bpo-44655: Include the name of the type in unset __slots__ attribute errors (GH-27199) (GH-27201) (cherry picked from commit f783428a2313a729ca8b539c5a86ff114b9ff375) Co-authored-by: Pablo Galindo Salgado <Pablogsal@gmail.com> Co-authored-by: Pablo Galindo Salgado <Pablogsal@gmail.com>