hyprland: fix hyprctl crash

`/tmp/hypr` must be present so `hyprctl` doesn't crash.

modules/services/window-managers/hyprland.nix

@@ -246,11 +246,13 @@ in {
 
       onChange = lib.mkIf (cfg.package != null) ''
         ( # Execute in subshell so we don't poision environment with vars
+          if [[ -d "/tmp/hypr" ]]; then
             # This var must be set for hyprctl to function, but the value doesn't matter.
             export HYPRLAND_INSTANCE_SIGNATURE="bogus"
             for i in $(${cfg.finalPackage}/bin/hyprctl instances -j | jq ".[].instance" -r); do
               HYPRLAND_INSTANCE_SIGNATURE=$i ${cfg.finalPackage}/bin/hyprctl reload config-only
             done
+          fi
         )
       '';
     };