[FIX] website_sale: wrong form selector on shipping change

Class `.hide` was replaced by `.d-none` with BS4 7f10b55a50
But the JS selector was still trying to retrieve the `.hide` form which lead to
an unexisting element, thus sending empty form.

Fixes #27714, closes #27774

addons/website_sale/static/src/js/website_sale.js

@@ -520,7 +520,7 @@ sAnimations.registry.websiteSaleCart = sAnimations.Class.extend({
         $new.removeClass('js_change_shipping');
         $new.addClass('border_primary');
 
-        var $form = $(ev.currentTarget).parent('div.one_kanban').find('form.hide');
+        var $form = $(ev.currentTarget).parent('div.one_kanban').find('form.d-none');
         $.post($form.attr('action'), $form.serialize()+'&xhr=1');
     },
     /**