test: simplify forEach() usage

Use an array literal instead of using split() on a very short string.

PR-URL: nodejs#30712
Reviewed-By: David Carlier <[email protected]>
Reviewed-By: Luigi Pinca <[email protected]>

Author: Trott

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

@@ -24,7 +24,7 @@ function once(cb) {
 }
 
 function finished(client, callback) {
-  'abort error end'.split(' ').forEach((e) => {
+  ['abort', 'error', 'end'].forEach((e) => {
     client.on(e, once(() => setImmediate(callback)));
   });
 }