There is an updated pull request by st3r4g against master on the void-packages repository

https://github.com/st3r4g/void-packages nicotine+-2.1.1
https://github.com/void-linux/void-packages/pull/25229

nicotine+: update to 2.1.1
Nicotine+ switched from `mutagen` to `pytaglib`, which is not in the repos yet.
I am not sure whether `GPL-3.0-only` or `GPL-3.0-or-later` is right for `pytaglib`

A patch file from https://github.com/void-linux/void-packages/pull/25229.patch is attached