Fixed compiler warning

Author: sakno

src/DotNext.Threading/Threading/QueuedSynchronizer.Queue.cs

@@ -1,6 +1,5 @@
 using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
-using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 
 namespace DotNext.Threading;