test: simplify test-http2-client-promisify-connect-error

There is no need to try to create a TCP connection that fails due to a
missing listening server. Also, the port used for the connection might
be used by another process when the connection is made.

PR-URL: https://github.com/nodejs/node/pull/57144
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>

test/parallel/test-http2-client-promisify-connect-error.js

@@ -8,14 +8,15 @@ const assert = require('assert');
 const http2 = require('http2');
 const util = require('util');
 
-const server = http2.createServer();
+const connect = util.promisify(http2.connect);
 
-server.listen(0, common.mustCall(() => {
-  const port = server.address().port;
-  server.close(common.mustCall(() => {
-    const connect = util.promisify(http2.connect);
-    assert.rejects(connect(`http://localhost:${port}`), {
-      code: 'ECONNREFUSED'
-    }).then(common.mustCall());
-  }));
-}));
+const error = new Error('Unable to resolve hostname');
+
+function lookup(hostname, options, callback) {
+  callback(error);
+}
+
+assert.rejects(
+  connect('http://hostname', { lookup }),
+  error,
+).then(common.mustCall());