adapt to improved async iteration

Author: janbuchar

src/crawlee/storage_clients/_file_system/_dataset_client.py

@@ -185,14 +185,10 @@ async def iterate_items(
                 f'by the {self.__class__.__name__} client.'
             )
 
-        # The native client returns a list rather than an async iterator,
-        # so we fetch all matching items and yield them one by one.
-        items: list[Any] = await self._native_client.iterate_items(
+        async for item in self._native_client.iterate_items(
             offset=offset,
             limit=limit,
             desc=desc,
             skip_empty=skip_empty,
-        )
-
-        for item in items:
+        ):
             yield item

src/crawlee/storage_clients/_file_system/_key_value_store_client.py

@@ -139,14 +139,10 @@ async def iterate_keys(
         exclusive_start_key: str | None = None,
         limit: int | None = None,
     ) -> AsyncIterator[KeyValueStoreRecordMetadata]:
-        # The native client returns a list, so we fetch all matching keys
-        # and yield them one by one.
-        items: list[dict[str, Any]] = await self._native_client.iterate_keys(
+        async for item in self._native_client.iterate_keys(
             exclusive_start_key=exclusive_start_key,
             limit=limit,
-        )
-
-        for item in items:
+        ):
             yield KeyValueStoreRecordMetadata(**item)
 
     @override