Bump serial-settings from 0c9df95 to d25f2ef

Bumps [serial-settings](https://github.com/quartiq/stabilizer) from `0c9df95` to `d25f2ef`.
- [Release notes](https://github.com/quartiq/stabilizer/releases)
- [Commits](quartiq/stabilizer@0c9df95...d25f2ef)

---
updated-dependencies:
- dependency-name: serial-settings
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>