message: guix: Update conservative space requirements
diff: @@ -13,11 +13,9 @@ We achieve bootstrappability by using Guix as a functional package manager.
  Conservatively, a x86_64 machine with:
  -- 4GB of free disk space on the partition that /gnu/store will reside in
  -- 24GB of free disk space on the partition that the Bitcoin Core git repository
  - resides in
  -
  -> Note: these requirements are slightly less onerous than those of Gitian builds
  +- 16GB of free disk space on the partition that /gnu/store will reside in
  +- 8GB of free disk space per platform triple you're planning on building (see
  + the `HOSTS` environment variable description)
  ## Setup
  