[FIX] website: remove faulty decorator
[FIX] website: remove faulty decorator

copy_menu_hierarchy is not a model function since it expects
to iterate on a recordset of websites

closes odoo/odoo#29723
ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo