nixosTests: fixup tests/common/resolver to work with a local resolver (#346793)

    services.bind.forwarders = lib.mkForce [];

    services.bind.zones = lib.singleton {

      name = ".";

      master = true;

      file = let

        addDot = zone: zone + lib.optionalString (!lib.hasSuffix "." zone) ".";

        mkNsdZoneNames = zones: map addDot (lib.attrNames zones);

        mkBindZoneNames = zones: map (zone: addDot zone.name) zones;

        mkBindZoneNames = zones: map addDot (lib.attrNames zones);

        getZones = cfg: mkNsdZoneNames cfg.services.nsd.zones

                     ++ mkBindZoneNames cfg.services.bind.zones;