#mjx don't specify JAX default backend

PiperOrigin-RevId: 785472058
Change-Id: Iba2d3e87dd2d78e6eee8fb579a760250a91b5d23

Author: Google DeepMind

mjx/mujoco/mjx/_src/io.py

@@ -148,7 +148,7 @@ def _resolve_impl_and_device(
   elif (has_impl, has_device) == (False, True):
     impl = _resolve_impl(device)
   else:
-    device = jax.devices(jax.default_backend())[0]
+    device = jax.devices()[0]
     logging.info('Using JAX default device: %s.', device)
     impl = _resolve_impl(device)