Fix mypy error

Author: araffin

stable_baselines3/common/save_util.py

@@ -181,7 +181,7 @@ def json_to_data(json_string: str, custom_objects: Optional[dict[str, Any]] = No
 @functools.singledispatch
 def open_path(
     path: Union[str, pathlib.Path, io.BufferedIOBase], mode: str, verbose: int = 0, suffix: Optional[str] = None
-) -> Union[io.BufferedWriter, io.BufferedReader, io.BytesIO]:
+) -> Union[io.BufferedWriter, io.BufferedReader, io.BytesIO, io.BufferedRandom]:
     """
     Opens a path for reading or writing with a preferred suffix and raises debug information.
     If the provided path is a derivative of io.BufferedIOBase it ensures that the file

tests/test_vec_envs.py

@@ -17,7 +17,7 @@
 from stable_baselines3.common.vec_env import DummyVecEnv, SubprocVecEnv, VecFrameStack, VecNormalize, VecVideoRecorder
 
 try:
-    import moviepy
+    import moviepy  # noqa: F401
 
     have_moviepy = True
 except ImportError: