replace one more UnknownIndex

Author: MarcoGorelli

pandas-stubs/_libs/tslibs/timestamps.pyi

@@ -19,9 +19,9 @@ from typing import (
 import numpy as np
 from pandas import (
     DatetimeIndex,
+    Index,
     TimedeltaIndex,
 )
-from pandas.core.indexes.base import UnknownIndex
 from pandas.core.series import (
     Series,
     TimedeltaSeries,
@@ -236,15 +236,15 @@ class Timestamp(datetime, SupportsIndex):
     @overload
     def __eq__(self, other: TimestampSeries) -> Series[bool]: ...  # type: ignore[overload-overlap]
     @overload
-    def __eq__(self, other: npt.NDArray[np.datetime64] | UnknownIndex) -> np_ndarray_bool: ...  # type: ignore[overload-overlap]
+    def __eq__(self, other: npt.NDArray[np.datetime64] | Index) -> np_ndarray_bool: ...  # type: ignore[overload-overlap]
     @overload
     def __eq__(self, other: object) -> Literal[False]: ...
     @overload
     def __ne__(self, other: Timestamp | datetime | np.datetime64) -> bool: ...  # type: ignore[overload-overlap] # pyright: ignore[reportOverlappingOverload]
     @overload
     def __ne__(self, other: TimestampSeries) -> Series[bool]: ...  # type: ignore[overload-overlap]
     @overload
-    def __ne__(self, other: npt.NDArray[np.datetime64] | UnknownIndex) -> np_ndarray_bool: ...  # type: ignore[overload-overlap]
+    def __ne__(self, other: npt.NDArray[np.datetime64] | Index) -> np_ndarray_bool: ...  # type: ignore[overload-overlap]
     @overload
     def __ne__(self, other: object) -> Literal[True]: ...
     def __hash__(self) -> int: ...