update link to use public video instead of unlisted

apps/docs/pages/guides/auth/auth-helpers/nextjs.mdx

@@ -626,7 +626,7 @@ const supabase = createClientComponentClient({ isSingleton: false })
 
 <div className="video-container">
   <iframe
-    src="https://www.youtube-nocookie.com/embed/SUS1t6Kq7-8"
+    src="https://www.youtube-nocookie.com/embed/ywvXGW6P4Gs"
     frameBorder="1"
     allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture"
     allowFullScreen