Remove obsolete DOMContentLoadedEventListener

app/assets/javascripts/pages/admin/groups/new/index.js

@@ -2,9 +2,9 @@ import initFilePickers from '~/file_pickers';
 import BindInOut from '../../../../behaviors/bind_in_out';
 import Group from '../../../../group';
 
-document.addEventListener('DOMContentLoaded', () => {
+(() => {
   BindInOut.initAll();
   initFilePickers();
 
   return new Group();
-});
+})();