Remove mention of replay protection

Author: daymxn

FirebaseAI/Sources/FirebaseAI.swift

@@ -38,13 +38,6 @@ public final class FirebaseAI: Sendable {
   ///     [App Check in Firebase AI Logic](https://firebase.google.com/docs/ai-logic/app-check).
   ///
   ///     _This flag is set to `false` by default._
-  ///
-  ///     > Important: Replay protection is not currently supported for the FirebaseAI backend.
-  ///     > While this feature is being developed, you can still migrate to using
-  ///     > limited-use tokens. Because limited-use tokens are backwards compatible, you can still
-  ///     > use them without replay protection. Due to their shorter TTL over standard App Check
-  ///     > tokens, they still provide a security benefit.
-  ///     >
   ///   > Migrating to limited-use tokens sooner minimizes disruption when support for replay
   ///   > protection is added.
   /// - Returns: A `FirebaseAI` instance, configured with the custom `FirebaseApp`.