[WAIT] - Adding nix ci to github actions

[sarcasticadmin]

Description of PR

Depends on: #509
Fixes: #510

Adding initial nix ci for nixpkgs-fmt

Previous Behavior

• No formatting present for .nix files

New Behavior

• Formatting and checks for *.nix

Tests

• Running the checks locally while inside a devShell

$ nix develop --command treefmt --fail-on-change --no-cache && git --no-pager diff
[INFO]: #nix: 8 files processed in 12.79ms

traversed 290 files
matched 8 files to formatters
left with 8 files after cache
of whom 0 files were re-formatted
all of this in 23ms

[sarcasticadmin]

FYI: Leveraging https://github.com/numtide/treefmt with the hopes of being able to add additional stanzas for https://github.com/numtide/treefmt/wiki#shell) and python via the black formatter (https://github.com/numtide/treefmt/wiki#python)

[sarcasticadmin]

@owendelong this ones been rebased and ready to go!

[sarcasticadmin]

Nevermind, moving this back to [WAIT]. The CI takes way to long in its current state: https://github.com/socallinuxexpo/scale-network/actions/runs/3820953513/jobs/6499648333 Going to see if theres a way to speed it up before we merge

[sarcasticadmin]

closing in favor of #625