Upgrade sb3 gymnasium

This MR updates many python packages and also python itself (to 3.11.5).

It also includes the changes for #130 (closed) (Remove CoppeliaSim and RLBench) and #133 (closed) (update MuJoCo).

Changes

• The installation is now simpler because mujoco can be installed as a python package
• Switched from gym to gymnasium. Because gymnasium does not include the robotics environments, we had to include the new package gymnasium-robotics.
• All the pip requirements are at the newest version, except numpy which needs to be a lower version for gymnasium-robotics.
• REMOVED Ant-environments and sac_mod.
• The MuJoCo environments had to be adjusted to the new MuJoCo version.
• The Optuna Sweepers had to be adjusted to the new Optuna version.
• Smoke tests now run on GPU

Fixes

• install command to install pytorch-cuda with conda
• loading tests now do not load policies that had been created before the test started

closes #130 (closed) #132 (closed) #133 (closed) #135 (closed)