fix: #718 reduce pyright ignore

Author: cmp0xff

pandas-stubs/core/indexes/accessors.pyi

@@ -429,7 +429,7 @@ class TimedeltaIndexProperties(
     _DatetimeRoundingMethods[TimedeltaIndex],
 ): ...
 
-class _dtDescriptor:
+class _dtDescriptor(CombinedDatetimelikeProperties):
     @overload
     def __get__(
         self, instance: Series[Timestamp], owner: Any