nix.tests: Remove dead code

        runCommand "test-nix-fallback-paths-version-equals-nix-stable" {

          paths = lib.concatStringsSep "\n" (builtins.attrValues (import ../../../../nixos/modules/installer/tools/nix-fallback-paths.nix));

        } ''

          # From nix test suite

          grepQuietInverse() {

            ! grep "$@" > /dev/null

          }

          if [[ "" != $(grep -v 'nix-${pkg.version}$' <<< "$paths") ]]; then

            echo "nix-fallback-paths not up to date with nixVersions.stable (nix-${pkg.version})"

            echo "The following paths are not up to date:"