Make it possible to specify path to s3 bucket as root

[quanvuong]

System Info

- `lerobot` version: 0.1.0
- Platform: Linux-6.5.0-1018-oracle-x86_64-with-glibc2.35
- Python version: 3.11.9
- Huggingface_hub version: 0.26.2
- Dataset version: 3.1.0
- Numpy version: 1.26.4
- PyTorch version (GPU?): 2.5.1+cu124 (False)
- Cuda version: 12040
- Using GPU in script?: No

Information

• One of the scripts in the examples/ folder of LeRobot
• My own task or dataset (give details below)

Reproduction

I am not able to specify an s3 path as root when creating a dataset.

Expected behavior

I have a very hacky PR here that allows me to do so. It would be great if lerobot supports s3 path as root directly.
quanvuong@c0ddff8