perf: improved pool return method by using a hashset for searching if the returning item is already queued

Engine.Core/Helpers/Pool.cs

@@ -10,22 +10,25 @@ public class Pool<T> : IPool<T>
 
     private readonly Func<T> generator = null!;
     private readonly Queue<T> queue = new();
+    private readonly HashSet<T> queuedHashes = [];
 
     public T Get()
     {
         if (!queue.TryDequeue(out T? result))
             result = generator();
 
+        queuedHashes.Remove(result);
         OnRemoved?.Invoke(this, result);
         return result;
     }
 
     public void Return(T item)
     {
-        if (queue.Contains(item))
+        if (queuedHashes.Contains(item))
             return;
 
         queue.Enqueue(item);
+        queuedHashes.Add(item);
         OnReturned?.Invoke(this, item);
     }