expand or show fields of Unpack[ ]

### Describe the Bug

np.power 's signature is

```py
(method) __call__: def __call__(
self: _UFunc_Nin2_Nout1[Literal['power'], Literal[18], None],
x1: ndarray,
x2: ArrayLike,
/,
out: EllipsisType | ndarray | tuple[ndarray] | None = None,
*,
dtype: _HasDType[dtype] | _HasNumPyDType[dtype] | dtype | list[Any] | str | _DTypeDict | tuple[Any, Any] | type[Any] | None = None,
where: _NestedSequence[_SupportsArray[dtype[numpy.bool]]] | _NestedSequence[builtins.bool] | _SupportsArray[dtype[numpy.bool]] | builtins.bool | None = ...,
casting: _CastingKind = ...,
order: _OrderKACF = ...,
subok: builtins.bool = ...,
signature: str | tuple[str | None, str | None, str | None] | None = ...,
**kwds: Unpack[_UFunc3Kwargs]
) -> ndarray: ...
```

I need to check the `_UFunc3Kwargs` definition to know the fields.

### Sandbox Link

_No response_

### (Only applicable for extension issues) IDE Information

_No response_