test: fix test-benchmark-cluster

test-benchmark-cluster needs to account for an option added in 973f324.

PR-URL: #30342
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Yongsheng Zhang <zyszys98@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

test/benchmark/test-benchmark-cluster.js

@@ -4,4 +4,9 @@ require('../common');
 
 const runBenchmark = require('../common/benchmark');
 
-runBenchmark('cluster', ['n=1', 'payload=string', 'sendsPerBroadcast=1']);
+runBenchmark('cluster', [
+  'n=1',
+  'payload=string',
+  'sendsPerBroadcast=1',
+  'serialization=json',
+]);