remove custom types defintions from datapoints module (#7814)

torchvision/transforms/v2/functional/_utils.py

 import functools
 import warnings
-from typing import Any, Callable, Dict, Type
+from typing import Any, Callable, Dict, List, Optional, Sequence, Type, Union
 
 import torch
 from torchvision import datapoints
 
+_FillType = Union[int, float, Sequence[int], Sequence[float], None]
+_FillTypeJIT = Optional[List[float]]
+
 
 def is_simple_tensor(inpt: Any) -> bool:
     return isinstance(inpt, torch.Tensor) and not isinstance(inpt, datapoints.Datapoint)