Update environment delete button

Button migration to update the CSS

app/assets/javascripts/environments/components/environment_delete.vue

 <script>
 /**
  * Renders the delete button that allows deleting a stopped environment.
- * Used in the environments table and the environment detail view.
+ * Used in the environments table.
  */
 
-import { GlTooltipDirective, GlIcon } from '@gitlab/ui';
+import { GlTooltipDirective, GlButton } from '@gitlab/ui';
 import { s__ } from '~/locale';
 import eventHub from '../event_hub';
-import LoadingButton from '../../vue_shared/components/loading_button.vue';
 
 export default {
   components: {
-    GlIcon,
-    LoadingButton,
+    GlButton,
   },
   directives: {
     GlTooltip: GlTooltipDirective,
@@ -54,16 +52,17 @@ export default {
 };
 </script>
 <template>
-  <loading-button
+  <gl-button
     v-gl-tooltip="{ id: $options.deleteEnvironmentTooltipId }"
     :loading="isLoading"
     :title="title"
     :aria-label="title"
-    container-class="btn btn-danger d-none d-md-block"
+    class="gl-display-none gl-display-md-block"
+    variant="danger"
+    category="primary"
+    icon="remove"
     data-toggle="modal"
     data-target="#delete-environment-modal"
     @click="onClick"
-  >
-    <gl-icon name="remove" />
-  </loading-button>
+  />
 </template>

spec/frontend/environments/environment_delete_spec.js

-import $ from 'jquery';
+import { GlButton } from '@gitlab/ui';
+
 import { shallowMount } from '@vue/test-utils';
 import DeleteComponent from '~/environments/components/environment_delete.vue';
-import LoadingButton from '~/vue_shared/components/loading_button.vue';
 import eventHub from '~/environments/event_hub';
 
-$.fn.tooltip = () => {};
-
 describe('External URL Component', () => {
   let wrapper;
 
@@ -17,7 +15,7 @@ describe('External URL Component', () => {
     });
   };
 
-  const findButton = () => wrapper.find(LoadingButton);
+  const findButton = () => wrapper.find(GlButton);
 
   beforeEach(() => {
     jest.spyOn(window, 'confirm');