feat: withoutManifest testing helper

[innocenzi]

Usage:

test('login screen can be rendered', function () {
    Vite::withoutManifest();

    this()
        ->get('/#')
        ->assertStatus(Response::HTTP_OK);
});

Fixes #123

[flick36]

Are there any advantages on using

if (! App::environment('local')) {
    return true;
}

over

if (App::environment('production')) {
    return true;
}

in line 196 of the src\Vite.php file

I think the only real use scenario for manifest is in production anyway, everything else can be without it and that way we don't have to put Vite::withoutManifest(); on each test? or anywhere really?

Edit: I mean for newcomers, one would expect everything to work out of the box, but the test that comes from default are failing, and since you added the withManifest() method as well, i believe is more convenient to use that if needed than having everything failing on the package install/replacement.