doc: fix typo in /api/dns.md

PR-URL: https://github.com/nodejs/node/pull/37312


Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Zijian Liu <lxxyxzj@gmail.com>
Reviewed-By: Pooja D P <Pooja.D.P@ibm.com>
Reviewed-By: Darshan Sen <raisinten@gmail.com>
Reviewed-By: Harshitha K P <harshitha014@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>