fix: iter ChunkedArray should return scalar value (#224)

Author: zen-xu

pyarrow-stubs/__lib_pxi/table.pyi

@@ -203,7 +203,7 @@ class ChunkedArray(_PandasConvertible[pd.Series], Generic[_Scalar_CoT]):
     @property
     def chunks(self) -> list[Array[_Scalar_CoT]]: ...
     def iterchunks(self) -> Generator[Array[_Scalar_CoT], None, None]: ...
-    def __iter__(self) -> Iterator[Array[_Scalar_CoT]]: ...
+    def __iter__(self) -> Iterator[_Scalar_CoT]: ...
     def to_pylist(
         self: ChunkedArray[Scalar[_BasicDataType[_AsPyType]]],
     ) -> list[_AsPyType | None]: ...