Merge branch 'jnnkl-remove-eventlistener-milestones-edit' into 'master'

Remove obsolete DOMContentLoadedEventListener

See merge request gitlab-org/gitlab!54926

app/assets/javascripts/pages/projects/milestones/edit/index.js

-import initForm from '../../../../shared/milestones/form';
+import initForm from '~/shared/milestones/form';
 
-document.addEventListener('DOMContentLoaded', () => initForm());
+initForm();