removing another unneeded using directive

Author: LPLafontaineB

Assets/Scripts/ConnectionManagement/ConnectionManager.cs

@@ -1,7 +1,6 @@
 using System;
 using System.Collections.Generic;
 using Unity.BossRoom.Utils;
-using Unity.Collections;
 using Unity.Netcode;
 using UnityEngine;
 using UUnity.BossRoom.ConnectionManagement;