You can add a resistance to limit current when running it at 12V. Spec sheet says 5V and 50 ohm coils so that's .1A. At 12V you'd need to add a 70 ohm resistor. It would need to be a 1 watt resistor.
This is the way we did it in the old days. It has the advantage of giving 12V across the coils when they are first energized, therefore more initial torque.