Limit W&B tag length to comply with 64‑character limit

[iory]

What this does

wandb.init() rejects any tag longer than 64 characters and returns:

400 Bad Request: invalid tag 'dataset:iory0710/apart_lift_a_white_faucet_start_from_same_pose_5hz'. must be between 1 and 64 characters

This pull request adds a safeguard that truncates every tag to ≤ 64 characters before passing it to wandb.init(). The change prevents the wandb.errors.CommError shown above while leaving the rest of the logging logic untouched.

Examples:

Title	Label
Fixes #544	(🐛 Bug)

How it was tested

Tested – Verified locally with the previously failing dataset name iory0710/apart_lift_a_white_faucet_start_from_same_pose_5hz.

How to checkout & try? (for the reviewer)

python lerobot/scripts/train.py   --dataset.repo_id=iory0710/apart_lift_a_white_faucet_start_from_same_pose_5hz   --policy.type=diffusion   --output_dir=outputs/train/diffusion_apart_test   --job_name=diffusion_apart_test   --wandb.enable=true   --policy.num_inference_steps=10   --policy.device=cpu   --steps=200000

[iory]

Can someone please approve the workflow so we can run it?