Merge branch 'jnnkl-remove-dom-content-loaded-wiki-index' into 'master'

Remove obsolete DOMContentLoadedEventListener

See merge request gitlab-org/gitlab!52778

app/assets/javascripts/pages/projects/wikis/index.js

 import initWikis from '~/pages/shared/wikis';
 
-document.addEventListener('DOMContentLoaded', initWikis);
+initWikis();