Merge branch 'jnnkl-remove-DomContent-Loaded-releases-index' into 'master'

Remove obsolete DOMContentLoadedEventListener

See merge request gitlab-org/gitlab!52776

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

 import initReleases from '~/releases/mount_index';
 
-document.addEventListener('DOMContentLoaded', initReleases);
+initReleases();