fixes missing default validation messages on FileUpload

[mariusticha]

Description

We encountered an unexpected behaviour in our running app after a composer update, so we investigated a little and found the origin in this PR: #12772

The addition of custom validation messages on a FileUpload has broken the default validation messages thrown in a failing rule.

Code Example:

// App\Rules\TestRule.php
public function validate(string $attribute, mixed $value, Closure $fail): void
{
    $fail('default validation message');
}


// TestComponent.php
FileUpload::make('test')
    ->rule(new TestRule)

Current Behaviour

On submit the error message shown says 'App\Rules\TestRule'

Expected Behaviour

On submit the error message shown says 'default validation message'

Functional changes

• Code style has been fixed by running the composer cs command.
• Changes have been tested to not break existing functionality.
• Documentation is up-to-date.

[aSeriousDeveloper]

This change also fixes the validation message that came with #12799.
Currently, the error message given is reverted to Illuminate\Validation\Rules\File.

[danharrin]

Thanks