feat(build): enable distributed builds and caching setup

- Added Nix distributed build configuration for multiple machines.
- Introduced caching setup with substituters and sandbox paths.
- Enabled optional build configurations with ccache support.

modules/nixos/services/build/default.nix

@@ -0,0 +1,23 @@
+{ config
+, lib
+, pkgs
+, ...
+}:
+with lib;
+with lib.metacfg;
+let
+  cfg = config.metacfg.build;
+in
+{
+  options.metacfg.build = with types; {
+    enable = mkBoolOpt false "Whether or not to enable the build config.";
+  };
+
+  config = mkIf cfg.enable {
+    programs.ccache.enable = true;
+    nix.settings.extra-sandbox-paths = [ "/var/cache/ccache" ];
+    environment.systemPackages = [
+      pkgs.ccache
+    ];
+  };
+}