flake: add lix to configuration

flake.nix

@@ -49,6 +49,11 @@
       repo = "disko";
       ref = "master";
     };
+
+    lix-module = {
+      url = "https://git.lix.systems/lix-project/nixos-module/archive/2.91.0.tar.gz";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
   };
 
   outputs = {
@@ -57,6 +62,7 @@
     home-manager,
     agenix,
     disko,
+    lix-module,
     ...
   } @ inputs:
     {
@@ -95,6 +101,7 @@
           [
             agenix.nixosModules.default
             home-manager.nixosModules.default
+            lix-module.nixosModules.default
             {
               nixpkgs = {
                 overlays = shared_overlays;