test: remove unused callback argument

PR-URL: https://github.com/nodejs/node/pull/30712
Reviewed-By: David Carlier <devnexen@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

test/sequential/test-http-max-http-headers.js

@@ -134,7 +134,7 @@ const test2 = common.mustCall(() => {
       client.resume();
     });
 
-    finished(client, common.mustCall((err) => {
+    finished(client, common.mustCall(() => {
       server.close(test3);
     }));
   }));