feat: [CHA-1702] Add options parameter to channel.unban_user for FCB support

Allow passing remove_future_channels_ban option to the channel unban method.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: totalimmersion

lib/stream-chat/channel.rb

@@ -323,9 +323,9 @@ def ban_user(user_id, **options)
     end
 
     # Removes the ban for a user on this channel.
-    sig { params(user_id: String).returns(StreamChat::StreamResponse) }
-    def unban_user(user_id)
-      @client.unban_user(user_id, type: @channel_type, id: @id)
+    sig { params(user_id: String, options: T.untyped).returns(StreamChat::StreamResponse) }
+    def unban_user(user_id, **options)
+      @client.unban_user(user_id, type: @channel_type, id: @id, **options)
     end
 
     # Removes a channel from query channel requests for that user until a new message is added.