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/unit/instance-initializers/feature-edition-test.js

@@ -32,7 +32,9 @@ module('Unit | Instance Initializer | feature-edition', function (hooks) {
   });
 
   hooks.afterEach(function () {
+    // eslint-disable-next-line ember/no-runloop
     run(this.instance, 'destroy');
+    // eslint-disable-next-line ember/no-runloop
     run(this.application, 'destroy');
   });