Remove incorrect localVue usage

localVue is required only with use method

ee/spec/frontend/environments_dashboard/components/environment_header_spec.js

-import { shallowMount, createLocalVue } from '@vue/test-utils';
+import { shallowMount } from '@vue/test-utils';
 import { GlLink, GlBadge } from '@gitlab/ui';
 import component from 'ee/environments_dashboard/components/dashboard/environment_header.vue';
 import Icon from '~/vue_shared/components/icon.vue';
 import ReviewAppLink from '~/vue_merge_request_widget/components/review_app_link.vue';
 
-const localVue = createLocalVue();
-
 describe('Environment Header', () => {
-  const Component = localVue.extend(component);
   let wrapper;
   let propsData;
 
@@ -27,11 +24,10 @@ describe('Environment Header', () => {
 
   describe('renders name and link to app', () => {
     beforeEach(() => {
-      wrapper = shallowMount(Component, {
+      wrapper = shallowMount(component, {
         sync: false,
         attachToDocument: true,
         propsData,
-        localVue,
       });
     });
 
@@ -64,11 +60,10 @@ describe('Environment Header', () => {
       propsData.environment.within_folder = true;
       propsData.environment.name = 'review/testing';
 
-      wrapper = shallowMount(Component, {
+      wrapper = shallowMount(component, {
         sync: false,
         attachToDocument: true,
         propsData,
-        localVue,
       });
     });
 
@@ -91,11 +86,10 @@ describe('Environment Header', () => {
     beforeEach(() => {
       propsData.hasErrors = true;
 
-      wrapper = shallowMount(Component, {
+      wrapper = shallowMount(component, {
         sync: false,
         attachToDocument: true,
         propsData,
-        localVue,
       });
     });
 
@@ -108,11 +102,10 @@ describe('Environment Header', () => {
     beforeEach(() => {
       propsData.hasPipelineFailed = true;
 
-      wrapper = shallowMount(Component, {
+      wrapper = shallowMount(component, {
         sync: false,
         attachToDocument: true,
         propsData,
-        localVue,
       });
     });
 

ee/spec/frontend/environments_dashboard/components/environment_spec.js

-import { shallowMount, createLocalVue } from '@vue/test-utils';
+import { shallowMount } from '@vue/test-utils';
 import component from 'ee/environments_dashboard/components/dashboard/environment.vue';
 import EnvironmentHeader from 'ee/environments_dashboard/components/dashboard/environment_header.vue';
 import Alert from 'ee/vue_shared/dashboards/components/alerts.vue';
 import Commit from '~/vue_shared/components/commit.vue';
 import environment from './mock_environment.json';
 
-const localVue = createLocalVue();
-
 describe('Environment', () => {
-  const Component = localVue.extend(component);
   let wrapper;
   let propsData;
 
@@ -16,10 +13,9 @@ describe('Environment', () => {
     propsData = {
       environment,
     };
-    wrapper = shallowMount(Component, {
+    wrapper = shallowMount(component, {
       sync: false,
       attachToDocument: true,
-      localVue,
       propsData,
     });
   });
@@ -95,10 +91,9 @@ describe('Environment', () => {
         last_deployment: null,
       },
     };
-    wrapper = shallowMount(Component, {
+    wrapper = shallowMount(component, {
       sync: false,
       attachToDocument: true,
-      localVue,
       propsData,
     });
 
@@ -115,10 +110,9 @@ describe('Environment', () => {
         },
       },
     };
-    wrapper = shallowMount(Component, {
+    wrapper = shallowMount(component, {
       sync: false,
       attachToDocument: true,
-      localVue,
       propsData,
     });
 

ee/spec/frontend/environments_dashboard/components/project_header_spec.js

-import { shallowMount, createLocalVue } from '@vue/test-utils';
+import { shallowMount } from '@vue/test-utils';
 import { GlButton } from '@gitlab/ui';
 import component from 'ee/environments_dashboard/components/dashboard/project_header.vue';
 import ProjectAvatar from '~/vue_shared/components/project_avatar/default.vue';
 
-const localVue = createLocalVue();
-
 describe('Project Header', () => {
-  const Component = localVue.extend(component);
   let wrapper;
   let propsData;
 
@@ -24,11 +21,10 @@ describe('Project Header', () => {
   });
 
   beforeEach(() => {
-    wrapper = shallowMount(Component, {
+    wrapper = shallowMount(component, {
       sync: false,
       attachToDocument: true,
       propsData,
-      localVue,
     });
   });