chore: Finalize Don't Set Fields to Null Anymore

Engine.Core/Behaviour.cs

@@ -54,7 +54,7 @@ public abstract class Behaviour : IBehaviour
 
     public bool Assign(IStateEnable stateEnable)
     {
-        if (_initialized)
+        if (Initialized)
             return false;
 
         _stateEnable = stateEnable;
@@ -65,7 +65,7 @@ public abstract class Behaviour : IBehaviour
 
     public bool Assign(IBehaviourController behaviourController)
     {
-        if (_behaviourController is not null)
+        if (Initialized)
             return false;
 
         _behaviourController = behaviourController;
@@ -90,9 +90,6 @@ public abstract class Behaviour : IBehaviour
         if (!Initialized)
             return false;
 
-        _behaviourController = null!;
-        _stateEnable = null!;
-
         Initialized = false;
         return true;
     }