Remove DOMContentLoaded Eventlisteners

Removing DOMContentLoaded Eventlisteners from
index files since the scripts
are embedded using the defer tag.

app/assets/javascripts/pages/groups/boards/index.js

@@ -2,8 +2,6 @@ import UsersSelect from '~/users_select';
 import ShortcutsNavigation from '~/behaviors/shortcuts/shortcuts_navigation';
 import initBoards from '~/boards';
 
-document.addEventListener('DOMContentLoaded', () => {
-  new UsersSelect(); // eslint-disable-line no-new
-  new ShortcutsNavigation(); // eslint-disable-line no-new
-  initBoards();
-});
+new UsersSelect(); // eslint-disable-line no-new
+new ShortcutsNavigation(); // eslint-disable-line no-new
+initBoards();

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

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

app/assets/javascripts/pages/groups/milestones/new/index.js

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

app/assets/javascripts/pages/groups/new/index.js

@@ -4,13 +4,11 @@ import Group from '~/group';
 import GroupPathValidator from './group_path_validator';
 import initFilePickers from '~/file_pickers';
 
-document.addEventListener('DOMContentLoaded', () => {
-  const parentId = $('#group_parent_id');
-  if (!parentId.val()) {
+const parentId = $('#group_parent_id');
+if (!parentId.val()) {
   new GroupPathValidator(); // eslint-disable-line no-new
-  }
-  BindInOut.initAll();
-  initFilePickers();
+}
+BindInOut.initAll();
+initFilePickers();
 
-  return new Group();
-});
+new Group(); // eslint-disable-line no-new

app/assets/javascripts/pages/groups/packages/index/index.js

 import initPackageList from '~/packages/list/packages_list_app_bundle';
 
-document.addEventListener('DOMContentLoaded', () => {
-  if (document.getElementById('js-vue-packages-list')) {
+if (document.getElementById('js-vue-packages-list')) {
   initPackageList();
-  }
-});
+}

ee/app/assets/javascripts/pages/groups/milestones/show/index.js

@@ -2,7 +2,5 @@ import '~/pages/groups/milestones/show/index';
 import initBurndownChart from 'ee/burndown_chart';
 import UserCallout from '~/user_callout';
 
-document.addEventListener('DOMContentLoaded', () => {
-  new UserCallout(); // eslint-disable-line no-new
-  initBurndownChart();
-});
+new UserCallout(); // eslint-disable-line no-new
+initBurndownChart();