Is there any recommended way to have guix gc only delete packages that aren't required to build anything? I've made a custom bash script that loops through the output of "guix gc --list-dead" and tells guix to delete any dead packages that have no --referers, but it's really slow (it can take several hours on my laptop). My first attempt was just telling guix to delete everything in --list-dead, but that seemed to still delete some things that were required to build other things currently on the system somewhere. Of course, running plain "guix gc" with no arguments is much faster, but requires redownloading loads of packages whenever I next go to pull, upgrade, or install anything.