update unlisted link to public link

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

@@ -528,7 +528,7 @@ This allows for the Supabase client to be easily instantiated in the correct con
 
 <div className="video-container">
   <iframe
-    src="https://www.youtube-nocookie.com/embed/f4yAnVgcJqI"
+    src="https://www.youtube-nocookie.com/embed/6Sb8R1PYhTY"
     frameBorder="1"
     allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture"
     allowFullScreen