test: replace forEach() with for ... of in test-readline-keys.js

PR-URL: https://github.com/nodejs/node/pull/50604
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

test/parallel/test-readline-keys.js

@@ -34,9 +34,9 @@ function addTest(sequences, expectedKeys) {
 
   keys = [];
 
-  sequences.forEach((sequence) => {
+  for (const sequence of sequences) {
     fi.write(sequence);
-  });
+  }
   assert.deepStrictEqual(keys, expectedKeys);
 }