doc: fix asyncLocalStorage.run() description

[PhakornKiong]

From the docs here

This methods runs a function synchronously outside of a context and return its return value. The store is not accessible within the callback function or the asynchronous operations created within the callback.

The description that store is not available when asynchronous operation is created within the callback is not accurate.

This PR add a setTimeout() within the example and update the description.

Fixes: #38022