docs(toast): update cdn version (#2801)

Author: liamdebeasi

static/usage/v6/toast/layout/demo.html

@@ -25,7 +25,7 @@
   </ion-app>
 
   <script type="module">
-    import { toastController } from 'https://cdn.jsdelivr.net/npm/@ionic/core@6.5.3-dev.11676303024.114a8ff3/dist/ionic/index.esm.js';
+    import { toastController } from 'https://cdn.jsdelivr.net/npm/@ionic/core@6/dist/ionic/index.esm.js';
     window.toastController = toastController;
   </script>