## Issue being fixed or feature implemented
Automated guix builds in CI when specifically requested
## What was done?
Any PR with the `build-guix` label added will automatically have the
Guix build ran and the hashes placed in the CI output to compare against
## How Has This Been Tested?
This PR
## Breaking Changes
None
## Checklist:
_Go over all the following points, and put an `x` in all the boxes that
apply._
- [x] I have performed a self-review of my own code
- [ ] I have commented my code, particularly in hard-to-understand areas
- [ ] I have added or updated relevant unit/integration/functional/e2e
tests
- [ ] I have made corresponding changes to the documentation
- [x] I have assigned this pull request to a milestone _(for repository
code-owners and collaborators only)_
