removing unnecessary using directive

Author: LPLafontaineB

Assets/Scripts/Gameplay/UI/NetworkSimulationUIMediator.cs

@@ -1,6 +1,5 @@
 using System;
 using System.Collections.Generic;
-using System.Linq;
 using System.Text.RegularExpressions;
 using TMPro;
 using Unity.Multiplayer.Tools.NetworkSimulator.Runtime;