nix: clean up infra

nix/infra/nix.nix

@@ -0,0 +1,33 @@
+{ lib, pkgs, ... }:
+
+{
+  nix = {
+    settings = {
+      substituters = [ "https://nix-community.cachix.org" ];
+      trusted-public-keys = [ "nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs=" ];
+      trusted-users = [ "root" ];
+      sandbox = true;
+      require-sigs = true;
+      max-jobs = "auto";
+      auto-optimise-store = true;
+      allowed-users = [ "*" ];
+      experimental-features = [
+        "nix-command"
+        "flakes"
+      ];
+      warn-dirty = true;
+      use-xdg-base-directories = true;
+      keep-going = true;
+      builders-use-substitutes = true;
+    };
+    distributedBuilds = true;
+    package = pkgs.lix;
+    nixPath = lib.mkForce [ "/etc/nix/path" ];
+  };
+
+  nixpkgs = {
+    config = {
+      allowUnfree = true;
+    };
+  };
+}