[10.x] Fix inconsistent type hint for $passwordTimeoutSeconds

[devfrey]

I've updated the type hint to be consistent with the type hint of the middleware's handle() method:
https://github.com/laravel/framework/blob/10.x/src/Illuminate/Auth/Middleware/RequirePassword.php#L67

An example that currently results in a static analysis error:

Route::view('/', 'home')->middleware(RequirePassword::using(passwordTimeoutSeconds: 10));

// Parameter $passwordTimeoutSeconds of static method Illuminate\Auth\Middleware\RequirePassword::using()
// expects string|null, int given.

[driesvints]

thanks!