Fixes #40463

This is related to change 1d56d0c

Motivation for this change

Example from the man page:

       security.acme.certs.<name>.domain
           Domain to fetch certificate for (defaults to the entry name)
           Type: string
           Default: "‹name›"
           Declared by:
               <nixpkgs/nixos/modules/security/acme.nix>

Example from the (local) manual:

Things done

• ✔️ Tested using sandboxing (nix.useSandbox on NixOS, or option build-use-sandbox in nix.conf on non-NixOS)
• 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)
• ✔️ Fits CONTRIBUTING.md.