test: unhardcode server port

This is needed to avoid possible conflicts when running multiple tests
in parallel

PR-URL: #27908
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Сковорода Никита Андреевич <chalkerx@gmail.com>
Reviewed-By: Ujjwal Sharma <usharma1998@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>

test/parallel/test-http-server-delete-parser.js

@@ -12,13 +12,13 @@ const server = http.createServer(common.mustCall((req, res) => {
   res.end();
 }));
 
-server.listen(1337, '127.0.0.1');
-server.unref();
-
-const req = http.request({
-  port: 1337,
-  host: '127.0.0.1',
-  method: 'GET',
-});
+server.listen(0, '127.0.0.1', common.mustCall(() => {
+  const req = http.request({
+    port: server.address().port,
+    host: '127.0.0.1',
+    method: 'GET',
+  });
+  req.end();
+}));
 
-req.end();
+server.unref();