nixos/listmonk: fixing datatype of options

nixos/modules/services/mail/listmonk.nix

···
 
       smtp = mkOption {
         type = listOf (submodule {
-          freeformType = with types; attrsOf (oneOf [ str int bool ]);
+          freeformType = with types; attrsOf anything;
 
           options = {
             enabled = mkEnableOption (lib.mdDoc "this SMTP server for listmonk");
···
       # TODO: refine this type based on the smtp one.
       "bounce.mailboxes" = mkOption {
         type = listOf
-          (submodule { freeformType = with types; oneOf [ str int bool ]; });
+          (submodule { freeformType = with types; listOf (attrsOf anything); });
         default = [ ];
         description = lib.mdDoc "List of bounce mailboxes";
       };