Remove DOMContentLoaded Eventlisteners

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

ee/app/assets/javascripts/pages/groups/analytics/cycle_analytics/index.js

 import initCycleAnalyticsApp from 'ee/analytics/cycle_analytics/index';
 
-document.addEventListener('DOMContentLoaded', initCycleAnalyticsApp);
+initCycleAnalyticsApp();

ee/app/assets/javascripts/pages/operations/environments/index.js

@@ -2,10 +2,8 @@ import Vue from 'vue';
 import EnvironmentDashboardComponent from 'ee/environments_dashboard/components/dashboard/dashboard.vue';
 import createStore from 'ee/vue_shared/dashboards/store';
 
-document.addEventListener(
-  'DOMContentLoaded',
-  () =>
-    new Vue({
+// eslint-disable-next-line no-new
+new Vue({
   el: '#js-environments',
   store: createStore(),
   components: {
@@ -16,5 +14,4 @@ document.addEventListener(
       props: this.$el.dataset,
     });
   },
-    }),
-);
+});

ee/app/assets/javascripts/pages/operations/index/index.js

@@ -2,10 +2,8 @@ import Vue from 'vue';
 import createStore from 'ee/vue_shared/dashboards/store';
 import DashboardComponent from 'ee/operations/components/dashboard/dashboard.vue';
 
-document.addEventListener(
-  'DOMContentLoaded',
-  () =>
-    new Vue({
+// eslint-disable-next-line no-new
+new Vue({
   el: '#js-operations',
   store: createStore(),
   components: {
@@ -21,5 +19,4 @@ document.addEventListener(
       },
     });
   },
-    }),
-);
+});

ee/app/assets/javascripts/pages/search/show/index.js

 import '~/pages/search/show/index';
 import UserCallout from '~/user_callout';
 
-document.addEventListener('DOMContentLoaded', () => new UserCallout());
+// eslint-disable-next-line no-new
+new UserCallout();

ee/app/assets/javascripts/pages/subscriptions/groups/edit/index.js

@@ -5,9 +5,7 @@ import GroupPathValidator from '~/pages/groups/new/group_path_validator';
 import BindInOut from '~/behaviors/bind_in_out';
 import Group from '~/group';
 
-document.addEventListener('DOMContentLoaded', () => {
-  mountProgressBar();
-  new GroupPathValidator();
-  BindInOut.initAll();
-  new Group();
-});
+mountProgressBar();
+new GroupPathValidator();
+BindInOut.initAll();
+new Group();

ee/app/assets/javascripts/pages/subscriptions/new/index.js

 import mountSubscriptionsApplication from 'ee/subscriptions/new';
 
-document.addEventListener('DOMContentLoaded', () => mountSubscriptionsApplication());
+mountSubscriptionsApplication();