[IMP] website: remove "add language" in mobile preview
[IMP] website: remove "add language" in mobile preview

Part of https://github.com/odoo/odoo/pull/30986
task-1939869
ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo