Clears all callback functions registered by register_next_step_handler().

        :param chat_id: The chat for which we want to clear next step handlers

def clear_step_handler_by_chat_id(self, chat_id):
        """
        Clears all callback functions registered by register_next_step_handler().

        :param chat_id: The chat for which we want to clear next step handlers
        """
        self.next_step_handlers[chat_id] = []

        if self.next_step_saver is not None:
            self.next_step_saver.start_save_timer()