fix: build and lots of obsolete warnings

modules/DebugTools/Handler.cs

@@ -4,13 +4,15 @@ using BotFramework.Enums;
 using BotFramework.Utils;
 using Kruzya.TelegramBot.Core.Extensions;
 using Kruzya.TelegramBot.Core.Service;
-using Newtonsoft.Json;
+using System.Text.Json;
 
 namespace West.TelegramBot.DebugTools;
 
 public class Handler : BotEventHandler
 {
     private readonly UserService _userService;
+    private static readonly JsonSerializerOptions DumpOptions = new() { WriteIndented = true };
+
 
     public Handler(UserService userService)
     {
@@ -26,7 +28,7 @@ public class Handler : BotEventHandler
         }
         var message = RawUpdate.Message!.ReplyToMessage ?? RawUpdate.Message;
         var text = HtmlString.Empty
-            .CodeWithStyle("language-json", JsonConvert.SerializeObject(message, Formatting.Indented));
+            .CodeWithStyle("language-json", JsonSerializer.Serialize(message, DumpOptions));
 
         await Bot.SendHtmlStringAsync(Chat, text, replyTo: message.MessageId);
     }