Remove denepdency on Nito.AsyncEx.Coordination

We don't really need async operations here, ReaderWriterLockSlim is enough

ArchiSteamFarm/Collections/ConcurrentEnumerator.cs

@@ -22,6 +22,7 @@
 using System;
 using System.Collections;
 using System.Collections.Generic;
+using System.Threading;
 using JetBrains.Annotations;
 
 namespace ArchiSteamFarm.Collections {
@@ -29,22 +30,24 @@ namespace ArchiSteamFarm.Collections {
 		public T Current => Enumerator.Current;
 
 		private readonly IEnumerator<T> Enumerator;
-		private readonly IDisposable Lock;
+		private readonly ReaderWriterLockSlim Lock;
 
 		object IEnumerator.Current => Current;
 
-		internal ConcurrentEnumerator([NotNull] IReadOnlyCollection<T> collection, [NotNull] IDisposable @lock) {
+		internal ConcurrentEnumerator([NotNull] IReadOnlyCollection<T> collection, [NotNull] ReaderWriterLockSlim @lock) {
 			if ((collection == null) || (@lock == null)) {
 				throw new ArgumentNullException(nameof(collection) + " || " + nameof(@lock));
 			}
 
+			@lock.EnterReadLock();
+
 			Lock = @lock;
 			Enumerator = collection.GetEnumerator();
 		}
 
 		public void Dispose() {
 			Enumerator.Dispose();
-			Lock.Dispose();
+			Lock.ExitReadLock();
 		}
 
 		public bool MoveNext() => Enumerator.MoveNext();