doc: move dns.promises to stable status

PR-URL: #26592
Reviewed-By: Anna Henningsen <[email protected]>
Reviewed-By: James M Snell <[email protected]>
Reviewed-By: Matteo Collina <[email protected]>
Reviewed-By: Michaël Zasso <[email protected]>

Author: cjihrig

doc/api/dns.md

@@ -588,7 +588,7 @@ earlier ones time out or result in some other error.
 
 ## DNS Promises API
 
-> Stability: 1 - Experimental
+> Stability: 2 - Stable
 
 The `dns.promises` API provides an alternative set of asynchronous DNS methods
 that return `Promise` objects rather than using callbacks. The API is accessible