Add mujoco-mjx dependency to pyproject.toml

Author: OliverSchw

pyproject.toml

@@ -29,6 +29,7 @@ dependencies = [
     "pytest-cov==5.0.0",
     "diffrax==0.5.1",
     "jax-dataclasses==1.6.0",
+    "mujoco-mjx==3.3.0",
 ]
 
 [tool.pytest.ini_options]
@@ -51,4 +52,4 @@ include = ["exciting_environments*"]  # package names should match these glob pa
 exciting_environments = ["exciting_environments/pmsm/*.mat"]
 
 [tool.black]
-line-length = 120
+line-length = 120