Fix coroutine state machine attribute.

Author: isadorasophia

src/Murder/Core/Engine/MonoWorld.cs

@@ -207,7 +207,9 @@ private Entity FetchNextFreeEffectEntity(out Coroutine coroutine)
             }
         }
 
-        Entity e = AddEntity();
+        Entity e = AddEntity(
+            new DoNotPersistEntityOnSaveComponent());
+
         _effectEntities.Add(e.EntityId);
         coroutine = new(_nextFreeEffectEntityIndex);
 

src/Murder/Services/CoroutineServices.cs

@@ -35,16 +35,20 @@ public static Entity RunCoroutine(this Entity e, IEnumerator<Wait> routine)
         return e;
     }
 
-    public static void FireAfter(this World world, float seconds, Action action)
+    public static Coroutine FireAfter(this World world, float seconds, Action action)
     {
-        Entity e = world.AddEntity();
-        e.RunCoroutine(WaitAndRun(seconds, action));
+        if (world is not MonoWorld murderWorld)
+        {
+            GameLogger.Warning("Unable to run coroutine on a world that is not MonoWorld.");
+            return new();
+        }
+
+        return murderWorld.RunCoroutine(WaitAndRun(seconds, action));
     }
 
     private static IEnumerator<Wait> WaitAndRun(float seconds, Action action)
     {
         yield return Wait.ForSeconds(seconds);
-
         action.Invoke();
     }
 }

src/Murder/StateMachines/CoroutineStateMachine.cs

@@ -8,7 +8,6 @@ namespace Murder.StateMachines;
 /// This CANNOT and WONT be serialized it is just a bad idea. Remember, we can't (or don't want to) serialize lambdas.
 /// </summary>
 [RuntimeOnly]
-[DoNotPersistEntityOnSave]
 public class CoroutineStateMachine : StateMachine
 {
     private readonly IEnumerator<Wait> _routine;