Use lib.meta.getExe

Signed-off-by: Nikolaos Karaolidis <nick@karaolidis.com>

users/configs/firefox/default.nix

@@ -1,4 +1,4 @@
-{ user ? throw "user argument is required" }: { pkgs, ... }:
+{ user ? throw "user argument is required" }: { lib, pkgs, ... }:
 
 {
   home-manager.users."${user.name}" = {
@@ -89,7 +89,7 @@
     };
 
     wayland.windowManager.hyprland.settings.bind = [
-      "$mod, b, exec, ${pkgs.firefox}/bin/firefox"
+      "$mod, b, exec, ${lib.meta.getExe pkgs.firefox}"
     ];
 
     home.persistence = {