Issue description

#44524 breaks the predictable interface naming in presence of eg. dhcpcd: https://hydra.nixos.org/build/79855242/nixlog/1

This blocks nixos-unstable.

Steps to reproduce

nix-build nixos/tests/predictable-interface-names.nix -A predictable

Technical details

Confirmed broken on 63d8458