Merge branch 'jnnkl-eventlistener-clusters-new' into 'master'

Remove obsolete DOMContentLoadedEventListener

See merge request gitlab-org/gitlab!53970

app/assets/javascripts/pages/projects/clusters/new/index.js

 import initNewCluster from '~/clusters/new_cluster';
 
-document.addEventListener('DOMContentLoaded', () => {
-  initNewCluster();
-});
+initNewCluster();