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

optipng: add changelog
https://github.com/void-linux/void-packages/pull/50579

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

`xchangelog` handles it fine, the file itself starts with non-printing characters* for some reason though:
![2024-05-28T22:53:50,555115731-04:00](https://github.com/void-linux/void-packages/assets/486393/19e58d7f-6976-4f15-b908-40f2bb494467)

*: byte sequence is `EF BB BF`
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