nixos/dovecot: remove option for unit name introspection (#470461)

    enableLmtp = mkEnableOption "starting the LMTP listener (when Dovecot is enabled)";

    hasNewUnitName = mkOption {

      type = types.bool;

      default = true;

      readOnly = true;

      internal = true;

      description = ''

        Inspectable option to confirm that the dovecot module uses the new

        `dovecot.service` name, instead of `dovecot2.service`.

        This is a helper added for the nixos-mailserver project and can be

        removed after branching off nixos-25.11.

      '';

    };

    protocols = mkOption {

      type = types.listOf types.str;

      default = [ ];

    environment.etc."dovecot/dovecot.conf".source = cfg.configFile;

    systemd.services.dovecot = {

      aliases = [ "dovecot2.service" ];

      description = "Dovecot IMAP/POP3 server";

      documentation = [

        "man:dovecot(1)"