scene changers should be clearing all spawned objects on scene exit

scripts/scene_changer.gd

@@ -27,6 +27,10 @@ func _on_body_entered(body: Node3D) -> void:
 			for i in spawned_stuff:
 				i.queue_free()
 
+func clear_spawned_objects():
+	for i in get_tree().current_scene:
+		if i.is_in_group("spawned"):
+			i.queue_free()
 
 func _on_start_activation_timeout() -> void:
 	active = true