Nix: XDPH isn't pushed to Cachix

[VlaDexa]

If you check the logs of xdph CI post run of cachix action, it just skips all packages and doesn't upload anything.

Latest skip from https://github.com/hyprwm/Hyprland/actions/runs/19671560974:

2025-11-25T14:16:47.6188612Z [2025-11-25 14:16:47][Info] Skipping /nix/store/nw838y47j6kjfcjfhsbdb069add4w88b-xdg-desktop-portal-hyprland-1.3.11+date=2025-10-25_4b88012