Icu 16546 upgrade ember for admin UI (#2793)

* v4.12.2...v5.12.0

* chore: 🤖 yarn.lock changes

* chore: 🤖 ember init blueprint changes

* chore: 🤖 yarn.lock file changes

* style: 💄 run linter and formatter

✅ Closes: https://hashicorp.atlassian.net/browse/ICU-16546

ui/admin/tests/integration/components/workers/worker/header/index-test.js

@@ -19,8 +19,8 @@ module(
       this.set('model', { id: 'w_123' });
 
       await render(hbs`
-      <Workers::Worker::Header @model={{this.model}} />
-    `);
+    <Workers::Worker::Header @model={{this.model}} />
+  `);
 
       assert.dom(this.element).includesText('w_123');
     });