migrate projects:environments:metrics to static bundle

app/assets/javascripts/dispatcher.js

@@ -43,11 +43,6 @@ var Dispatcher;
       });
 
       switch (page) {
-        case 'projects:environments:metrics':
-          import('./pages/projects/environments/metrics')
-            .then(callDefault)
-            .catch(fail);
-          break;
         case 'projects:merge_requests:index':
         case 'projects:issues:index':
         case 'projects:issues:show':

app/assets/javascripts/pages/projects/environments/metrics/index.js

 import monitoringBundle from '~/monitoring/monitoring_bundle';
 
-export default monitoringBundle;
+document.addEventListener('DOMContentLoaded', monitoringBundle);