Install tools to fix volume hotkeys

configuration.nix

@@ -3,9 +3,8 @@
 # https://search.nixos.org/options and in the NixOS manual (`nixos-help`).
 
 { config, lib, pkgs, ... }:
-let
-  unstable = import <nixpkgs-unstable> { config = { allowUnfree = true; }; };
-in {
+
+{
   nix.settings.experimental-features = [ "nix-command" "flakes" ];
   imports =
     [ # Include the results of the hardware scan.
@@ -169,8 +168,11 @@ in {
     file
     gnumake
     awscli2
-    unstable.code-cursor
+    code-cursor
     pavucontrol
+    pulseaudio
+    xbindkeys
+    pamixer
     libnotify
     alsa-tools
     aircrack-ng