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

https://github.com/joshuakraemer/void-packages dosbox-png-check
https://github.com/void-linux/void-packages/pull/14475

dosbox: remove modification for libpng check
The `pre_configure` modification of the libpng check is no longer necessary, because the relevant bug has been resolved upstream, see https://sourceforge.net/p/dosbox/bugs/345/

A patch file from https://github.com/void-linux/void-packages/pull/14475.patch is attached