Ensuring nonexistent item can't be selected

scenes/ui/quick_slots.gd

@@ -56,6 +56,8 @@ func get_selected_item() -> String:
 	return _items[_selected_item]
 
 func select_item_index(slot_index: int) -> void:
+	if slot_index >= _items.size(): return
+
 	_selected_item = slot_index
 	update_highlighted_slot()
 	InventoryManager.quick_slot_item_changed.emit(get_selected_item())