Add brightnessctl for framework screen.

nodes/hosts/nixwork/configuration.nix

@@ -9,6 +9,7 @@
     [ # Include the results of the hardware scan.
       ./hardware-configuration.nix
       inputs.nixos-hardware.nixosModules.framework-16-7040-amd
+      ./programs/brightnessctl.nix
       ./programs/fwupd.nix
       ./programs/powertop.nix
       ./programs/sof-firmware.nix

nodes/hosts/nixwork/programs/brightnessctl.nix

@@ -0,0 +1,6 @@
+{ pkgs, ... }: {
+  environment.systemPackages = [
+    pkgs.brightnessctl
+  ];
+}
+