Currently, the method `on_attach_callback` is never called on any Widget in the systray. Calling `on_attach_callback` is required if any systray widget uses an OWL component via the ComponentWrapper. Without the callback, the component is never considered mounted to the DOM and no event handler is triggered. closes odoo/odoo#46566 Related: odoo/enterprise#8887 Signed-off-by: Aaron Bohy (aab) <aab@odoo.com>