Upgrade to v3.0.0

Update from Mujoco-Py to Mujoco.
Update from Gym to Gymnasium, with full alignment with Gymnasium >= 1.0
Expose the reward functions, referred to as "V1", from the original Meta-World release.
Maintain support for previous method of creating environments, as well as adding the support to use gym.make interface
Removal of 'V1' environments
Restructure of repository organization

Meta-World v2.0.0

This release is a release of the code before the Farama Foundation started maintaining Meta-World.