Progress simulation by running all agents once asynchronously.

def async_step(self):
        """Progress simulation by running all agents once asynchronously.
        """
        assert len(self._agents_to_act) == 0
        self._init_step()
        t = time.time()
        aiomas.run(until=self.env.trigger_all())
        self._agents_to_act = []
        self._step_processing_time = time.time() - t
        self._finalize_step()