dns: remove Resolver#cancel() from promises API

Because reasons.

PR-URL: #21264
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>

Author: cjihrig

doc/api/dns.md

@@ -622,14 +622,6 @@ The following methods from the `dnsPromises` API are available:
 * [`resolver.resolveTxt()`][`dnsPromises.resolveTxt()`]
 * [`resolver.reverse()`][`dnsPromises.reverse()`]
 
-#### resolver.cancel()
-<!-- YAML
-added: REPLACEME
--->
-
-Cancel all outstanding DNS queries made by this resolver. The corresponding
-`Promise`s will be rejected with an error with code `ECANCELLED`.
-
 ### dnsPromises.getServers()
 <!-- YAML
 added: REPLACEME

lib/internal/dns/promises.js

@@ -212,7 +212,6 @@ class Resolver {
   }
 }
 
-Resolver.prototype.cancel = CallbackResolver.prototype.cancel;
 Resolver.prototype.getServers = CallbackResolver.prototype.getServers;
 Resolver.prototype.setServers = CallbackResolver.prototype.setServers;
 Resolver.prototype.resolveAny = resolveMap.ANY = resolver('queryAny');