[12.x] Allow not having "fakerphp/faker" installed

[SjorsO]

I have somewhat of an obsession to keep my dependency count low and my bundle size small. For basic applications I can get away with using only:

"require": {  
    "php": "^8.4",  
    "laravel/framework": "^12.0",  
    "laravel/tinker": "^2.10.1"  
},  
"require-dev": {  
    "fakerphp/faker": "^1.23",  
    "laravel/pint": "^1.24",  
    "mockery/mockery": "^1.6",  
    "phpunit/phpunit": "^11.5.3"  
},

Right now, I can't remove "fakerphp/faker", because that causes factories to throw exceptions (even if my factories don't use Faker).

This PR allows me to remove Faker from my dependencies. With the above set of minimal packages, this shrinks my development vendor directory by:

• Size: 72 mb -> 61 mb (-11 mb, -15%)
• Files: 8040 -> 7526 (-514 files, -7%)

For reference, the fake() helper already checks if Faker is available before it is registered.

Also, one of the reasons the creator of Faker decided to sunset the original Faker package was because of its environmental impact. This PR allows environmentally conscious Laravel developers to remove Faker from their dependencies.

When not using Faker in basic applications, it is still possible to write good factories:

class UserFactory extends Factory  
{  
    public function definition(): array  
    {  
        return [  
            'uuid' => Str::uuid()->toString(),  
            'first_name' => Arr::random(['Hank', 'Bill', 'Dale', 'Bobby', 'Boomhauer']),  
            'email' => 'email-'.mt_rand().'.@example.com',  
        ];  
    }
}