afterstep is unmaintained upstream, with the last time it was touched being six years ago and appearing to have been on life support for at least a decade. it's had many drive-by and cleanup fixes as part of larger upgrades (binutils, gcc) over the years, which seems disproportionate for a package that is unmaintained in Nixpkgs. additionally, it depends on GTK 2, which is being removed from Nixpkgs. thus, we drop it entirely.