fix: load script

dogs-video-object-tracking-dataset.py

@@ -165,6 +165,6 @@ class DogsVideoObjectTrackingDataset(datasets.GeneratorBasedBuilder):
                 "id": image_id,
                 "name": name,
                 "image": file,
-                "mask": f"{data}/masks/{file}",
+                "mask": os.path.join(data, "masks", file),
                 "shapes": shapes,
             }