This does not include any automation for the release branch, but
is based on the configuration of https://github.com/NixOS/nix/pull/12349
pre-commit run -a nixfmt-rfc-style
This ensures just `nix build`-ing the flake doesn't forget to run all
tests. One can still specifiy specific attributes to just build one
thing.
Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>