mujoco-py fails to install on GPU node that has nvidia-smi

[boegel]

mujoco-py's setup.py detects presence of nvidia-smi, and is too smart for its own good by default

https://github.com/openai/mujoco-py/blob/a13903b82f1ab316815e63b3575526005b3b2ae1/mujoco_py/builder.py#L27

    File "setup.py", line 29, in run
      import mujoco_py  # noqa: force build
    File "/tmp/eb-r3ftepka/pip-req-build-uv9v_78g/mujoco_py/__init__.py", line 2, in <module>
      from mujoco_py.builder import cymj, ignore_mujoco_warnings, functions, MujocoException
    File "/tmp/eb-r3ftepka/pip-req-build-uv9v_78g/mujoco_py/builder.py", line 505, in <module>
      cymj = load_cython_ext(mujoco_path)
    File "/tmp/eb-r3ftepka/pip-req-build-uv9v_78g/mujoco_py/builder.py", line 76, in load_cython_ext
      _ensure_set_env_var("LD_LIBRARY_PATH", get_nvidia_lib_dir())
    File "/tmp/eb-r3ftepka/pip-req-build-uv9v_78g/mujoco_py/builder.py", line 121, in _ensure_set_env_var
      raise Exception("\nMissing path to your environment variable. \n"
  Exception:
  Missing path to your environment variable.
  Current values LD_LIBRARY_PATH=/software/MuJoCo/2.1.1-GCCcore-11.2.0/lib:...
  Please add following line to .bashrc:
  export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/lib/nvidia
  Building wheel for mujoco-py (PEP 517): finished with status 'error'
  ERROR: Failed building wheel for mujoco-py

This shenanigans can be overridden by setting $MUJOCO_PY_FORCE_CPU, cfr. https://github.com/openai/mujoco-py/blob/a13903b82f1ab316815e63b3575526005b3b2ae1/mujoco_py/builder.py#L75C23-L75C42