Docker drop privileges

### Prerequisites

- [x] I have checked the [Wiki](https://github.com/AdguardTeam/AdGuardHome/wiki) and [Discussions](https://github.com/AdguardTeam/AdGuardHome/discussions) and found no answer

- [x] I have searched other issues and found no duplicates

- [x] I want to request a feature or enhancement and not ask a question

### The problem

The docker version of Adguard Home always runs as root as can be seen in the Dockerfile, based on other discussions I have seen about running without root in Linux, I believe the same can be achieved with docker. Losing any kind of auto updating features seems not that important when running via docker as you can just pull the latest image.

### Proposed solution

Drop privileges for the container or at least provide the option to the user of running as specified UID and a GUID.

### Alternatives considered and additional information

_No response_