LeRobot v0.4.1 released

Hugging Face's robot learning library LeRobot has released v0.4.1, an upgrade from v0.4.0. Key updates include adding EnvHub support for loading environments from the hub, adding libero to the pypi package, fixing a training data access bottleneck to speed up training, and fixing a critical bug in dataset_tools. This version also includes a video_key spelling fix, dependency upgrades, and installation documentation updates.