Avoid casting with `numpy()` in `multiprocessing.py` about pytorch-lightning HOT 1 OPEN

def get_extra_results(self, trainer: "pl.Trainer") -> Dict[str, Any]:
        """Gather extra state from the Trainer and return it as a dictionary for sending back to the main process. To
        avoid issues with memory sharing, we cast the data to numpy.

        Args:
            trainer: reference to the Trainer.

        Returns:
            A dictionary with items to send back to the main process where :meth:`update_main_process_results` will
            process this output.

        """
        return {"callback_metrics": trainer.callback_metrics}