[feature request] add new repo_id name instead of overwriting the current repo

[yanan1116]

https://github.com/huggingface/lerobot/blob/main/src/lerobot/datasets/v30/convert_dataset_v21_to_v30.py

when run python -m lerobot.datasets.v30.convert_dataset_v21_to_v30 and push to hub, the new v3 version dataset will replace the old v2.1 repo.

how about add a parameter that allows to input a new repo name instead of simple replacement.

thanks.