There's a merged pull request on the void-packages repository

routinator: update to 0.12.1 and add runit service.
https://github.com/void-linux/void-packages/pull/37848

Description:
Update to 0.12.0 and add runit service.

- [x] Create a runit service

No longer relevant for now: 
- Build and include documentation
- Add missing python packages required for documentation
    - python3-sphinx-tabs
    - python3-sphinx-copybutton

#### Testing the changes
- I tested the changes in this PR: **YES**
Release notes at https://github.com/NLnetLabs/routinator/releases

#### Local build testing
- I built this PR locally for my native architecture, (x86_64-glibc, x86_64-musl)
- I built this PR locally for these architectures:
  - aarch64-musl
  - armv7l
  - armv6l-musl
  - x86_64-musl