Remove jQuery .attr from the Fomantic modal cancel buttons (#30113)

- Switched from jQuery `attr` to plain javascript `setAttribute`
- Tested the modals and they work as before

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Co-authored-by: silverwind <me@silverwind.io>
(cherry picked from commit f47e00d9d3c3bd58b5944a29c4ff5cec0357520a)

web_src/js/modules/fomantic/modal.js

@@ -19,7 +19,9 @@ function ariaModalFn(...args) {
       // In such case, the "Enter" key will trigger the "cancel" button instead of "ok" button, then the dialog will be closed.
       // It breaks the user experience - the "Enter" key should confirm the dialog and submit the form.
       // So, all "cancel" buttons without "[type]" must be marked as "type=button".
-      $(el).find('form button.cancel:not([type])').attr('type', 'button');
+      for (const button of el.querySelectorAll('form button.cancel:not([type])')) {
+        button.setAttribute('type', 'button');
+      }
     }
   }
   return ret;