chore: use alias & constants (#2785)

* chore: use alias and constants

* fix(rl): solve circular dependecy

* chore: nit right constant

* chore: pre-commit

* chore(script): conflict tokenizer train

---------

Signed-off-by: Steven Palma <imstevenpmwork@ieee.org>

src/lerobot/envs/libero.py

@@ -29,6 +29,8 @@ from gymnasium import spaces
 from libero.libero import benchmark, get_libero_path
 from libero.libero.envs import OffScreenRenderEnv
 
+from lerobot.processor import RobotObservation
+
 
 def _parse_camera_names(camera_name: str | Sequence[str]) -> list[str]:
     """Normalize camera_name into a non-empty list of strings."""
@@ -237,7 +239,7 @@ class LiberoEnv(gym.Env):
         env.reset()
         return env
 
-    def _format_raw_obs(self, raw_obs: dict[str, Any]) -> dict[str, Any]:
+    def _format_raw_obs(self, raw_obs: RobotObservation) -> RobotObservation:
         images = {}
         for camera_name in self.camera_name:
             image = raw_obs[camera_name]
@@ -313,7 +315,7 @@ class LiberoEnv(gym.Env):
         info = {"is_success": False}
         return observation, info
 
-    def step(self, action: np.ndarray) -> tuple[dict[str, Any], float, bool, bool, dict[str, Any]]:
+    def step(self, action: np.ndarray) -> tuple[RobotObservation, float, bool, bool, dict[str, Any]]:
         if action.ndim != 1:
             raise ValueError(
                 f"Expected action to be 1-D (shape (action_dim,)), "