There's a merged pull request on the void-packages repository

mkvtoolnix: update to 64.0.0
https://github.com/void-linux/void-packages/pull/34736

Description:
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#### Testing the changes
- I tested the changes in this PR: **YES**

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#### New package
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#### Local build testing
- I built this PR locally for my native architecture, (`x86_64`)
- I built this PR locally for these architectures (if supported. mark crossbuilds):
  - `aarch64` (cross)
  - `aarch64-musl` (cross)
  - `armv6l` (cross)
  - `armv6l-musl` (cross)
  - `armv7l` (cross)
  - `armv7l-musl` (cross)
  - `i686`
  - `x86_64-musl`