chore: update rbac 404 (#90)

Author: chdeskur

fern/products/docs/pages/authentication/rbac.mdx

@@ -46,8 +46,7 @@ sequenceDiagram
         alt User has required role
             F->>U: Show restricted content
         else User lacks required role
-            F->>R: Redirect to login page
-            R->>A: Authenticate user
+            F->>U: User is shown a 404 page
         end
     else No cookie
         F->>R: Redirect to login page