chore: update ad code

Author: yyx990803

themes/vue/layout/partials/ad.ejs

@@ -1,11 +1,8 @@
 <div id="ad">
-  <script>
-    (function () {
-      var s = document.createElement('script')
-      s.setAttribute('async', '')
-      s.src = '//cdn.carbonads.com/carbon.js?zoneid=1673&serve=C6AILKT&placement=vuejs'
-      s.id = '_carbonads_js'
-      document.getElementById('ad').appendChild(s)
-    })()
+  <script
+    async
+    type="text/javascript"
+    src="//cdn.carbonads.com/carbon.js?serve=CKYIK2QU&placement=vuejsorg"
+    id="_carbonads_js">
   </script>
 </div>