doc: fix typo in worker_threads.md
"Buffer.alloc()" -> "Buffer.allocUnsafe()"
Buffer.alloc() does not use the internal Buffer pool.
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
"Buffer.alloc()" -> "Buffer.allocUnsafe()"
Buffer.alloc() does not use the internal Buffer pool.