fix import

pytorch_lightning/utilities/types.py

@@ -17,12 +17,13 @@
  - Types used in public hooks (as those in the `LightningModule` and `Callback`) should be public (no leading `_`)
 """
 from pathlib import Path
-from typing import Any, Dict, Iterator, List, Mapping, Optional, Sequence, Type, TypedDict, Union
+from typing import Any, Dict, Iterator, List, Mapping, Optional, Sequence, Type, Union
 
 import torch
 from torch.optim import Optimizer
 from torch.utils.data import DataLoader
 from torchmetrics import Metric
+from typing_extensions import TypedDict
 
 _NUMBER = Union[int, float]
 _METRIC = Union[Metric, torch.Tensor, _NUMBER]