[A11y] Form JavaScript: Support for <button formnovalidate>

src/pretix/static/pretixpresale/js/ui/main.js

@@ -234,6 +234,7 @@ var form_handlers = function (el) {
 
 function setup_basics(el) {
     el.find("form").attr("novalidate", true).on("submit", function (e) {
+        if (e.originalEvent.submitter.formNoValidate) return;
         if (!this.checkValidity()) {
             var input = this.querySelector(":invalid:not(fieldset)");
             (input.labels[0] || input).scrollIntoView();