add missing type hints in datetimeindex shallow copy

Author: annika-rudolph

pandas/core/indexes/datetimelike.py

@@ -846,9 +846,9 @@ def take(
     @doc(Index._shallow_copy)
     def _shallow_copy( # type: ignore[override]
         self,
-        values,
+        values: np.ndarray,
         name: Hashable = no_default,
-        level_codes=no_default,
+        level_codes: np.ndarray = no_default,
     ) -> Self:
         name = self._name if name is no_default else name
         result = self._simple_new(values, name=name, refs=self._references)