chore: coroutine manager moved to correct directory

Engine.Core/Systems/CoroutineManager.cs

@@ -0,0 +1,34 @@
+using System.Collections;
+using System.Collections.Generic;
+
+namespace Engine.Core;
+
+public class CoroutineManager : Behaviour, IUpdate
+{
+    private readonly List<IEnumerator> enumerators = [];
+
+    public IEnumerator StartCoroutine(IEnumerator enumerator)
+    {
+        enumerators.Add(enumerator);
+        return enumerator;
+    }
+
+    public void StopCoroutine(IEnumerator enumerator)
+    {
+        enumerators.Remove(enumerator);
+    }
+
+    void IUpdate.Update()
+    {
+        for (int i = enumerators.Count - 1; i >= 0; i--)
+        {
+            if (enumerators[i].Current is ICoroutineYield coroutineYield && coroutineYield.Yield())
+                continue;
+
+            if (!enumerators[i].MoveNext())
+                enumerators.RemoveAt(i);
+        }
+    }
+
+    public CoroutineManager() => Priority = int.MinValue;
+}