fix: set the default device to gpu for minimal working example

Author: PSilvestre

repro/sec7_3_rl_train/impls/tempo_ppo.py

@@ -183,7 +183,7 @@ def get_tempo_ppo_executor(  # noqa: C901
         # NOTE: Default obs shape for trivial env
         "obs_shape": (3, 4, 4),
         "seed": 0,
-        "dev": "fake-gpu",
+        "dev": "gpu",
         "iterations": 50,
         # PPO hyperparams
         "gamma": 0.99,