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

https://github.com/lxeiqr/void-packages mpd-shout
https://github.com/void-linux/void-packages/pull/23292

mpd: add shoutcast support
Enables libshout support in mpd by default

A patch file from https://github.com/void-linux/void-packages/pull/23292.patch is attached