fix: remove usused onReadMessage method

ts/models/conversation.ts

@@ -471,26 +471,6 @@ export class ConversationModel extends Backbone.Model<ConversationAttributes> {
     return true;
   }
 
-  public async onReadMessage(message: MessageModel, readAt: number) {
-    // We mark as read everything older than this message - to clean up old stuff
-    //   still marked unread in the database. If the user generally doesn't read in
-    //   the desktop app, so the desktop app only gets read syncs, we can very
-    //   easily end up with messages never marked as read (our previous early read
-    //   sync handling, read syncs never sent because app was offline)
-
-    // We queue it because we often get a whole lot of read syncs at once, and
-    //   their markRead calls could very easily overlap given the async pull from DB.
-
-    // Lastly, we don't send read syncs for any message marked read due to a read
-    //   sync. That's a notification explosion we don't need.
-    return this.queueJob(() =>
-      this.markReadBouncy(message.get('received_at') as any, {
-        sendReadReceipts: false,
-        readAt,
-      })
-    );
-  }
-
   public async getUnreadCount() {
     const unreadCount = await Data.getUnreadCountByConversation(this.id);