Remove unused vulnerability report

ee/app/assets/javascripts/security_dashboard/vulnerability_report_init.js

@@ -2,7 +2,6 @@ import Vue from 'vue';
 import { DASHBOARD_TYPES } from 'ee/security_dashboard/store/constants';
 import { parseBoolean } from '~/lib/utils/common_utils';
 import UnavailableState from './components/shared/empty_states/unavailable_state.vue';
-import VulnerabilityReport from './components/shared/vulnerability_report.vue';
 import apolloProvider from './graphql/provider';
 import createRouter from './router';
 import createStore from './store';
@@ -19,7 +18,7 @@ const getVulnerabilityComponent = (dashboardType) => {
     case DASHBOARD_TYPES.INSTANCE:
       return InstanceVulnerabilityReport;
     default:
-      return VulnerabilityReport;
+      throw new Error('unknown_dashboard');
   }
 };