If nobody beats me to it, I might propose a change to `.github/workflows/build.yml` sometime during the coming weeks to make use of a virtual framebuffer.
See 65d4b66. I opted for an X based solution with `xvfb-run` as that can easily be installed via the official Ubuntu repositories that the workflow already relies on.
The Mingw and macOS builds were out of scope, as the former doesn't run tests and the latter is not defined here (and xvfb-run doesn't work on Darwin).
@zen0bit: Sorry, I have no experience with Void Linux ^^; You might get more exposure by posting this as a separate issue. You could still link it to this PR and the accompanying issue.