vendor issue on forge deploy

hi not sure about section in forum. I have change RegistersUsers.php in /vendor/laravel/ui/auth_backend

 public function register(Request $request)
    {
        // ...

        $user = $this->create($request->all());

        event(new Registered($user));
        $user->channel()->create([
            'name' => $request->channel_name,
            'slug' => Str::slug($request->channel_name, '-'),
            'uid' => uniqid(true),
        ]);
       
        // ...
    }

but vendor is set inside git ignore file. that why It never update on push and deploy on forge laravel.

how to fix this issue ?

regards