doc: fix duplicate word "of of" in postMessageToThread

PR-URL: #62917
Reviewed-By: Marco Ippolito <marcoippolito54@gmail.com>
Reviewed-By: Jacob Smith <jacob@frende.me>
Reviewed-By: Daeyeon Jeong <daeyeon.dev@gmail.com>
Reviewed-By: Darshan Sen <raisinten@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Stephen Belanger <admin@stephenbelanger.com>

Author: watilde

doc/api/worker_threads.md

@@ -513,7 +513,7 @@ parent or child of the current thread.
 If the two threads are parent-children, use the [`require('node:worker_threads').parentPort.postMessage()`][]
 and the [`worker.postMessage()`][] to let the threads communicate.
 
-The example below shows the use of of `postMessageToThread`: it creates 10 nested threads,
+The example below shows the use of `postMessageToThread`: it creates 10 nested threads,
 the last one will try to communicate with the main thread.
 
 ```mjs