There is an updated 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/39870

mkvtoolnix: update to 71.1.0
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#### Testing the changes
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A patch file from https://github.com/void-linux/void-packages/pull/39870.patch is attached