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

https://github.com/Eluminae/void-packages mopidy-spotify
https://github.com/void-linux/void-packages/pull/18351

New package: mopidy-spotify-4.0.1


A patch file from https://github.com/void-linux/void-packages/pull/18351.patch is attached