infrastructure-checkpoint-compatibi-when-using-asyncpostgressaver-alist-to-read-checkp-e692fb68

THEN In the _load_checkpoint_tuple method, replace the direct unpacking of value["checkpoint"].get("channel_values") with a default empty dict: use value["checkpoint"].get("channel_values") or {}. This gracefully handles None values and maintains compatibility with checkpoints from previous versions.

checkpoint_channel_values = value["checkpoint"].get("channel_values") or {}
"channel_values": {
    **checkpoint_channel_values,
    **self._load_blobs(value["channel_values"]),
}