Convert to flakes parts syntax

flake.nix

@@ -9,21 +9,22 @@
     disko.inputs.nixpkgs.follows = "nixpkgs";
   };
 
-  outputs = { self, nixpkgs, ... }: 
-  let
-    allSystems = [ "x86_64-linux" "aarch64-linux" ];
-  in 
-  {
-    devShells = nixpkgs.lib.genAttrs allSystems (system: 
+  outputs = inputs@{ flake-parts, ... }:
+    flake-parts.lib.mkFlake { inherit inputs; } {
+      systems = [
+        "x86_64-linux"
+        "aarch64-linux"
+      ];
+
+      perSystem = { system, pkgs, ... }: 
       let
-        pkgs = import nixpkgs { inherit system; };
         tofuPkg = pkgs.opentofu.withPlugins (p: [
           pkgs.terraform-providers.hcloud
           pkgs.terraform-providers.null
           pkgs.terraform-providers.external
         ]);
       in {
-        default = pkgs.mkShell {
+        devShells.default = pkgs.mkShell {
           buildInputs = [ 
             tofuPkg
             pkgs.terraform-ls
@@ -34,7 +35,6 @@
             alias tofu-apply="tofu apply -var-file=secret.tfvars"
           '';
         };
-      }
-    );
-  };
+      };
+    };
 }