feat: Refactor to use flake-parts and import inventory and users thru the flake parts

parts/fleet-option.nix

@@ -1,9 +0,0 @@
-# Flake-parts wrapper for fleet-option.nix
-{ inputs, self, lib, config, ... }:
-let
-  fleetModule = import ../fleet/fleet-option.nix { inherit inputs lib; };
-  inventoryModule = import ../inventory.nix { };
-in
-{
-  imports = [ fleetModule inventoryModule ];
-}

parts/nixos-configurations.nix

@@ -1,6 +1,17 @@
 # NixOS configurations generated from fleet
-{ inputs, self, lib, config, ... }:
 {
+  inputs,
+  self,
+  lib,
+  pkgs,
+  config,
+  ...
+}:
+{
+  imports = [
+    ../fleet/fleet-option.nix
+  ];
+
   flake.nixosConfigurations =
     let
       fleet = self.lib.mkFleet { inherit inputs lib config; };