refactor: memory leaks caused by behaviour collectors fixed

Engine.Core/BehaviourCollector.cs

@@ -17,8 +17,6 @@ public class BehaviourCollector<T> : IBehaviourCollector<T> where T : class
     public IReadOnlyList<T> Behaviours => behaviours;
     public IUniverse Universe { get; private set; } = null!;
 
-    public T this[Index index] => behaviours[index];
-
     public BehaviourCollector() { }
     public BehaviourCollector(IUniverse universe) => Assign(universe);
 
@@ -98,7 +96,4 @@ public class BehaviourCollector<T> : IBehaviourCollector<T> where T : class
         OnUnassigned?.Invoke(this);
         return true;
     }
-
-    public IEnumerator<T> GetEnumerator() => behaviours.GetEnumerator();
-    IEnumerator IEnumerable.GetEnumerator() => behaviours.GetEnumerator();
 }