style: Switch to nixfmt from nixpkgs-fmt

Most of the ecosystem has moved to this formatter,
and many people configured their editors to autoformat it with this formatter.

Closes: https://git.snix.dev/snix/snix/issues/62
Change-Id: Icf39e7836c91fc2ae49fbe22a40a639105bfb0bd
Reviewed-on: https://cl.snix.dev/c/snix/+/30671
Reviewed-by: Florian Klink <flokli@flokli.de>
Tested-by: besadii
Autosubmit: Ilan Joselevich <personal@ilanjoselevich.com>

ops/modules/hetzner-cloud.nix

@@ -1,11 +1,21 @@
-{ config, lib, pkgs, modulesPath, ... }:
+{
+  config,
+  lib,
+  pkgs,
+  modulesPath,
+  ...
+}:
 let
   cfg = config.infra.hardware.hetzner-cloud;
-  inherit (lib) types mkOption mkEnableOption mkIf;
+  inherit (lib)
+    types
+    mkOption
+    mkEnableOption
+    mkIf
+    ;
 in
 {
-  imports =
-    [ (modulesPath + "/profiles/qemu-guest.nix") ];
+  imports = [ (modulesPath + "/profiles/qemu-guest.nix") ];
 
   options.infra.hardware.hetzner-cloud = {
     enable = mkEnableOption "the Hetzner Cloud hardware profile";
@@ -40,7 +50,10 @@ in
         }
       ];
 
-      dns = [ "2a01:4ff:ff00::add:1" "2a01:4ff:ff00::add:2" ];
+      dns = [
+        "2a01:4ff:ff00::add:1"
+        "2a01:4ff:ff00::add:2"
+      ];
     };
 
     boot.loader.systemd-boot.enable = true;