packages: Improve detection for guix.

[arjanadriaanse]

Description

If a separate guix-home manager is not desirable, it could probably be joined with guix-user instead, similar to how other user packages are handled for nix.

Features

• detect packages managed by guix home

[hykilpikonna]

Thank you for your contribution!

This PR is merged into hyfetch since this repo (dylanaraps/neofetch) seems no longer maintained.

HyFetch is a fork of neofetch with LGBTQ pride flags, but the repo also maintains an updated version of the original neofetch, addressing many pull requests that are not merged in the original repo.

Read the "Running Updated Original Neofetch" section for more info!