CLEAN: use preferred pattern for index accessors (#346)

* WIP: TimedeltaIndex accessors

* remove dtl to make mypy happy

* demonstrate possible bug

Author: Dr-Irv

pandas-stubs/core/indexes/accessors.pyi

@@ -157,7 +157,7 @@ _DTRoundingMethodReturnType = TypeVar(
     TimedeltaSeries,
     TimestampSeries,
     DatetimeIndex,
-    # TimedeltaIndex
+    TimedeltaIndex,
 )
 
 class _DatetimeRoundingMethods(Generic[_DTRoundingMethodReturnType]):
@@ -378,31 +378,8 @@ class DatetimeIndexProperties(
         self, axis: int | None = ..., ddof: int = ..., skipna: bool = ...
     ) -> Timedelta: ...
 
-# For some reason, using TimedeltaIndex as an argument to _DatetimeRoundingMethods
-# doesn't work for pyright.  So we just make the rounding methods explicit here.
 class TimedeltaIndexProperties(
     Properties,
     _TimedeltaPropertiesNoRounding[Index, Index],
-    # _DatetimeRoundingMethods[TimedeltaIndex],
-):
-    def round(
-        self,
-        freq: str | BaseOffset | None,
-        ambiguous: Literal["raise", "infer", "NaT"] | np_ndarray_bool = ...,
-        nonexistent: Literal["shift_forward", "shift_backward", "NaT", "raise"]
-        | Timedelta = ...,
-    ) -> TimedeltaIndex: ...
-    def floor(
-        self,
-        freq: str | BaseOffset | None,
-        ambiguous: Literal["raise", "infer", "NaT"] | np_ndarray_bool = ...,
-        nonexistent: Literal["shift_forward", "shift_backward", "NaT", "raise"]
-        | Timedelta = ...,
-    ) -> TimedeltaIndex: ...
-    def ceil(
-        self,
-        freq: str | BaseOffset | None,
-        ambiguous: Literal["raise", "infer", "NaT"] | np_ndarray_bool = ...,
-        nonexistent: Literal["shift_forward", "shift_backward", "NaT", "raise"]
-        | Timedelta = ...,
-    ) -> TimedeltaIndex: ...
+    _DatetimeRoundingMethods[TimedeltaIndex],
+): ...