chore: Inherit Doc

[ChinaMoli]

When using VSCode with the laravel/vs-code-extension plugin installed, the plugin automatically determines and modifies the return value of Auth::user() to the corresponding model (\App\Models\User)

However, \Tymon\JWTAuth\JWTGuard::user() duplicates the return value, causing the return value modified by the plug-in to not take effect, so this PR modifies the comment of the user() method so that it inherits from the document.

laravel/vs-code-extension added file

// vendor/_laravel_ide/_auth.php
<?php

namespace Illuminate\Contracts\Auth;

interface Guard
{
    /**
     * @return \App\Models\User|null
     */
    public function user();
}

Before modification

After modification