Dotnet version upgrade

Room/Room.cs

@@ -3,7 +3,6 @@ using System.Text.Json;
 using System.Text.RegularExpressions;
 using MauMau_Server.Room.Messages;
 using MauMau_Server.Websockets;
-using Microsoft.AspNet.SignalR.Messaging;
 
 namespace MauMau_Server.Room;
 
@@ -11,7 +10,7 @@ public class Room
 {
     private readonly IRoomManager _roomManager;
     private readonly string _roomId;
-    public readonly List<ConnectionInstance> Connections = new();
+    public readonly List<ConnectionInstance> Connections = [];
     public ConnectionInstance? Host;
     public RoomType RoomType;