test: increase coverage in lib/internal/dns/promises.js

Add a test for the only uncovered code in lib/internal/dns/promises.js.

PR-URL: #27330
Reviewed-By: Yongsheng Zhang <[email protected]>
Reviewed-By: Ruben Bridgewater <[email protected]>
Reviewed-By: Michael Dawson <[email protected]>

Author: Trott

test/parallel/test-dns-lookupService.js

@@ -18,3 +18,12 @@ assert.throws(
     syscall: 'getnameinfo'
   }
 );
+
+assert.rejects(
+  dns.promises.lookupService('127.0.0.1', 80),
+  {
+    code: 'ENOENT',
+    message: 'getnameinfo ENOENT 127.0.0.1',
+    syscall: 'getnameinfo'
+  }
+);