fix data outpye type

flash/vision/classification/data.py

@@ -86,7 +86,7 @@ def _load_data_dir(cls, data: Any, dataset: Optional[AutoDataset] = None) -> Lis
             # labels might not contain the complete set of ids so that you can infer the total
             # number of classes to train in your dataset.
             dataset.num_classes = len(data)
-            out: List[str, int] = []
+            out: List[Tuple[str, int]] = []
             for p, label in data:
                 if os.path.isdir(p):
                     files_list: List[str] = os.listdir(p)