it improves package correctness and keeps cross-compilation in good
health
there aren't many uses of buildCrystalPackage in nixpkgs yet so imo its
safe to turn it on
python builder, rust build, go builder, and others all turn it on
continuation of #109595
pkgconfig was aliased in 2018, however, it remained in
all-packages.nix due to its wide usage. This cleans
up the remaining references to pkgs.pkgsconfig and
moves the entry to aliases.nix.
python3Packages.pkgconfig remained unchanged because
it's the canonical name of the upstream package
on pypi.
