Adjust xfail mark: xfail if no GPU (on CI)

Signed-off-by: Fabrice Normandin <normandf@mila.quebec>

project/algorithms/jax_ppo_test.py

@@ -3,7 +3,6 @@
 import dataclasses
 import functools
 import operator
-import sys
 import time
 from collections.abc import Callable, Iterable, Sequence
 from logging import getLogger
@@ -206,7 +205,7 @@ def test_ours_with_trainer(
         algo.visualize(ts_i, gif_path=gif_path, eval_rng=eval_rng_i)
 
 
-@pytest.mark.xfail(sys.platform == "darwin" and IN_GITHUB_CI, reason="Fails on macOS in CI.")
+@pytest.mark.xfail(not torch.cuda.is_available(), reason="Fails on CPU in the CI")
 def test_results_are_same_with_or_without_jax_trainer(
     results_ours: tuple[PPOState, EvalMetrics],
     results_ours_with_trainer: tuple[PPOState, EvalMetrics],