removed unused using directives

Author: ShadauxCat

com.unity.netcode.gameobjects/Tests/Runtime/NetworkTransformAnticipationTests.cs

@@ -1,8 +1,6 @@
 using System;
-using System.Collections;
 using System.Collections.Generic;
 using System.Linq;
-using System.Numerics;
 using NUnit.Framework;
 using Unity.Netcode.Components;
 using Unity.Netcode.TestHelpers.Runtime;