remove flake8 offending newline added by black

Author: smanolloff

src/imitation/data/huggingface_utils.py

@@ -16,7 +16,6 @@ class TrajectoryDatasetSequence(Sequence[types.Trajectory]):
 
     def __init__(self, dataset: datasets.Dataset):
         """Construct a TrajectoryDatasetSequence."""
-
         # TODO: this is just a temporary workaround for
         #  https://github.com/huggingface/datasets/issues/5517
         #  switch to .with_format("numpy") once it's fixed