@GrapheneOS The police will try to force you to do so, but this lawyer says that you are not obliged to. In fact, the right approach is to remain silent and then call a lawyer, and the police will probably try to dissuade you from doing so by putting a lot of pressure on you.
Christophe Boutry is a ex DGSI agent and a user/defender of GOS.
https://www.youtube.com/watch?v=aA4uCef4sFo
The problem is that some people in the comments claim that the police can force you to give them your PIN/passwords, but I would trust a lawyer more than random on the internet.
As a French citizen, it's not very clear.

@falken It's an example of their stance towards privacy and individual rights. UK has similar issues with starting to demand encryption backdoors but France is way worse. UK is not going after us in any way.
We're very likely moving both servers we have in the UK elsewhere. One was only a temporary stopgap because it was provided as a sponsored dedicated server as an update mirror. The other is an instance for our ns1 anycast cluster and we've determined Amsterdam is likely better for anycast.