http: improve writeEarlyHints by avoiding for-of loop

PR-URL: #59958
Refs: https://github.com/nodejs/node/blob/main/doc/contributing/primordials.md#unsafe-array-iteration
Reviewed-By: Daeyeon Jeong <[email protected]>
Reviewed-By: Antoine du Hamel <[email protected]>

Author: haramj

lib/_http_server.js

@@ -330,7 +330,9 @@ ServerResponse.prototype.writeEarlyHints = function writeEarlyHints(hints, cb) {
 
   head += 'Link: ' + link + '\r\n';
 
-  for (const key of ObjectKeys(hints)) {
+  const keys = ObjectKeys(hints);
+  for (let i = 0; i < keys.length; i++) {
+    const key = keys[i];
     if (key !== 'link') {
       head += key + ': ' + hints[key] + '\r\n';
     }