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

https://github.com/newbluemoon/void-packages libheif
https://github.com/void-linux/void-packages/pull/27531

libheif-devel: depends on libde265-devel
libde265 is required in its .pc-file

A patch file from https://github.com/void-linux/void-packages/pull/27531.patch is attached