I have noticed the same thing on my 2021 GTI SE 170… the handle bars squeak a bit when turning them. There is some slight resistance it seems from a seal of some sort or maybe the steering shroud is rubbing on the handle bars? I have used WD-40 with an adjustable nozzle to put the nozzle down between the handle bars and the shroud that mates up with the handle bars, and sprayed around the area where the handle bars turn. It has helped, but there is something maybe more internal or not easily accessible that is causing the squeak. It isn’t significant enough for me to be concerned, so I haven’t pursued it further. But maybe someone else has actually dug into what the cause is. It seems to be a simple rubber seal rubbing against something - not the actual steering shaft corroded and squeaking.