Merge branch 'jnnkl-remove-dom-content-loaded-pipeline-chart' into 'master'

Remove obsolete DOMContentLoadedEventListener

See merge request gitlab-org/gitlab!51454

app/assets/javascripts/pages/projects/pipelines/charts/index.js

 import initProjectPipelinesChartsApp from '~/projects/pipelines/charts/index';
 
-document.addEventListener('DOMContentLoaded', initProjectPipelinesChartsApp);
+initProjectPipelinesChartsApp();