Remove obsolete DOMContentLoadedEventListener

app/assets/javascripts/pages/admin/index.js

@@ -2,10 +2,8 @@ import initAdminStatisticsPanel from '../../admin/statistics_panel/index';
 import initVueAlerts from '../../vue_alerts';
 import initAdmin from './admin';
-document.addEventListener('DOMContentLoaded', initVueAlerts);
-document.addEventListener('DOMContentLoaded', () => {
-  const statisticsPanelContainer = document.getElementById('js-admin-statistics-container');
-  initAdmin();
-  initAdminStatisticsPanel(statisticsPanelContainer);
-});
+initVueAlerts();
+const statisticsPanelContainer = document.getElementById('js-admin-statistics-container');
+initAdmin();
+initAdminStatisticsPanel(statisticsPanelContainer);