allow to nullify access token

Author: Guilherme Souza

Sources/Realtime/V2/RealtimeChannelV2.swift

@@ -193,15 +193,15 @@ public final class RealtimeChannelV2: Sendable {
     )
   }
 
-  public func updateAuth(jwt: String) async {
+  public func updateAuth(jwt: String?) async {
     logger?.debug("Updating auth token for channel \(topic)")
     await push(
       RealtimeMessageV2(
         joinRef: mutableState.joinRef,
         ref: socket.makeRef().description,
         topic: topic,
         event: ChannelEvent.accessToken,
-        payload: ["access_token": .string(jwt)]
+        payload: ["access_token": jwt.map { .string($0) } ?? .null]
       )
     )
   }

Sources/Realtime/V2/RealtimeClientV2.swift

@@ -347,7 +347,7 @@ public final class RealtimeClientV2: Sendable {
     }
 
     for channel in channels.values {
-      if let token, channel.status == .subscribed {
+      if channel.status == .subscribed {
         await channel.updateAuth(jwt: token)
       }
     }