nixos/gitea: add ma27 as maintainer

nixos/modules/services/misc/gitea.nix

···
       timerConfig.OnCalendar = cfg.dump.interval;
     };
   };
-  meta.maintainers = with lib.maintainers; [ srhb ];
+  meta.maintainers = with lib.maintainers; [ srhb ma27 ];
 }