fix(): sort from config is ignored

[JeromeSiau]

Hi!

There is a small typo in the getNavigationSort function.
It uses set instead of get, so even if we set a sort in the config file, it is currently ignored

[what-the-diff]

🎉 PR Summary 🎉

• Configuration Adjustment in EmailResource.php
  We made a switcheroo in how we interact with our config settings. Now, instead of setting a value with Config::set(...), we're now grabbing it using Config::get(...). It's like asking the system politely for a piece of information instead of telling it what to store. 😄

Remember, these kinds of changes help us retrieve the correct configuration values more efficiently and reduce potential bugs down the road. 🐛➡️🚫

[RickDBCN]

Good catch! Many thanks!