[CI] Clean up loader-mujoco deps

Author: stephane-caron

tox.ini

@@ -44,10 +44,6 @@ commands =
 deps =
     pytest
     mujoco >=2.2.1
-    pinocchio-py{38,39}: pin >=2.6.10
-    pybullet: pybullet >=3.2.5
-    robomeshcat-py{38,39}: robomeshcat >= 1.0.3
-    yourdfpy: yourdfpy >=0.0.52
 commands =
     mujoco: pytest --import-mode=importlib tests/loaders/test_mujoco.py