Just let air out until you don't have vibration. Make sure to let it out of the rear to, as it contributes to front vibration. I'd keep the front at 90% of rear pressure, so just lower both until you're comfortable.

Fancy carbon bars and stem might dampen the vibration, but they're not going to correct the inefficiency of the vibration under them. If your bike is vibrating like that, you're essentially climbing and descending little 2mm hills every 10mm. Just like climbing and descending slows you down on bigger hills, it will slow you down on tiny hills.

Let the tires soak that stuff up so your mass isn't going up and down (or so your carbon bars and stem are dampening out your pedaling power through vibration).

Note that small changes in air pressure make very little difference in rolling resistance, and that rolling resistance is measured on a smooth surface. If you're riding on a rough surface, that's a big chunk of your rolling resistance.