Motivation for this change

#108313

This is a failing test and this is intended. To confirm this test succeeds when the bug is not present:

$ git checkout b0587cfbd1d6ec5730032891712ea260c177ab4f # one before the staging merge
$ git checkout 74aa934c7619bed649086ff4b781d7fb645f144d nixos/tests/shadow.nix
$ nix-build nixos/tests/shadow.nix

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS linux)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Ensured that relevant documentation is up to date
• Fits CONTRIBUTING.md.