style: format all nix files with nixfmt

modules/nixos/settings.nix

@@ -3,13 +3,16 @@
     # nix settings
     settings = {
       # enable flakes and nix-command
-      experimental-features = [ "nix-command" "flakes" ];
+      experimental-features = [
+        "nix-command"
+        "flakes"
+      ];
       # auto-optimize my nix-store
       auto-optimise-store = true;
       # use all cores
-      max-jobs = "auto";  
+      max-jobs = "auto";
       # use all available cores per job
-      cores = 0;          
+      cores = 0;
       # add trusted substituters (binary caches)
       substituters = [
         "https://cache.nixos.org"
@@ -21,7 +24,7 @@
         "nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs="
       ];
     };
-    
+
     # enable automatic garbage collection
     gc = {
       automatic = true;
@@ -29,9 +32,12 @@
       options = "--delete-older-than 7d";
     };
   };
-  
+
   # add trusted users (able to modify the nix store)
-  nix.settings.trusted-users = [ "root" "@wheel" ];
+  nix.settings.trusted-users = [
+    "root"
+    "@wheel"
+  ];
 
   # allow unfree packages (steam, protonvpn, discord, etc.)
   nixpkgs.config.allowUnfree = true;