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/index.html

@@ -1,26 +1,29 @@
-<!doctype html>
 <!--
  Copyright (c) HashiCorp, Inc.
  SPDX-License-Identifier: BUSL-1.1
 -->
 
+<!DOCTYPE html>
 <html>
   <head>
-    <meta charset="utf-8" />
+    <meta charset="utf-8">
     <title>Admin Tests</title>
-    <meta name="description" content="" />
-    <meta name="viewport" content="width=device-width, initial-scale=1" />
+    <meta name="description" content="">
+    <meta name="viewport" content="width=device-width, initial-scale=1">
 
-    {{content-for "head"}} {{content-for "test-head"}}
+    {{content-for "head"}}
+    {{content-for "test-head"}}
 
-    <link rel="stylesheet" href="{{rootURL}}assets/vendor.css" />
-    <link rel="stylesheet" href="{{rootURL}}assets/admin.css" />
-    <link rel="stylesheet" href="{{rootURL}}assets/test-support.css" />
+    <link rel="stylesheet" href="{{rootURL}}assets/vendor.css">
+    <link rel="stylesheet" href="{{rootURL}}assets/admin.css">
+    <link rel="stylesheet" href="{{rootURL}}assets/test-support.css">
 
-    {{content-for "head-footer"}} {{content-for "test-head-footer"}}
+    {{content-for "head-footer"}}
+    {{content-for "test-head-footer"}}
   </head>
   <body>
-    {{content-for "body"}} {{content-for "test-body"}}
+    {{content-for "body"}}
+    {{content-for "test-body"}}
 
     <div id="qunit"></div>
     <div id="qunit-fixture">
@@ -35,6 +38,7 @@
     <script src="{{rootURL}}assets/admin.js"></script>
     <script src="{{rootURL}}assets/tests.js"></script>
 
-    {{content-for "body-footer"}} {{content-for "test-body-footer"}}
+    {{content-for "body-footer"}}
+    {{content-for "test-body-footer"}}
   </body>
 </html>