message: Fix type annotation in xla_extension.
diff: @@ -358,7 +358,7 @@ Buffer = DeviceArray
  class Executable:
  client: Client
  def local_logical_device_ids(self) -> List[Tuple[int, int]]: ...
  - def local_devices(self): List[Device]: ...
  + def local_devices(self) -> List[Device]: ...
  def size_of_generated_code_in_bytes(self) -> int: ...
  def delete(self) -> None: ...
  def execute(self, arguments: Sequence[DeviceArray]) -> List[DeviceArray]: ...
  