SB3-Contrib v1.8.0

Warning
Stable-Baselines3 (SB3) v1.8.0 will be the last one to use Gym as a backend.
Starting with v2.0.0, Gymnasium will be the default backend (though SB3 will have compatibility layers for Gym envs).
You can find a migration guide here.
If you want to try the SB3 v2.0 alpha version, you can take a look at PR #1327.

RL Zoo3 (training framework): https://github.com/DLR-RM/rl-baselines3-zoo

To upgrade:

pip install stable_baselines3 sb3_contrib rl_zoo3 --upgrade

or simply (rl zoo depends on SB3 and SB3 contrib):

pip install rl_zoo3 --upgrade

Breaking Changes:

• Removed shared layers in mlp_extractor (@AlexPasqua)
• Upgraded to Stable-Baselines3 >= 1.8.0

New Features:

• Added stats_window_size argument to control smoothing in rollout logging (@jonasreiher)

Bug Fixes:

Deprecations:

Others:

• Moved to pyproject.toml
• Added github issue forms
• Fixed Atari Roms download in CI
• Fixed sb3_contrib/qrdqn/*.py type hints
• Switched from flake8 to ruff

Documentation:

• Added warning about potential crashes caused by check_env in the MaskablePPO docs (@AlexPasqua)