There is a new pull request by mvf against master on the void-packages repository

https://github.com/mvf/void-packages pr/mkvtoolnix
https://github.com/void-linux/void-packages/pull/18711

mkvtoolnix: update to 43.0.0


A patch file from https://github.com/void-linux/void-packages/pull/18711.patch is attached