Fix Webhook Issue in PHP SDK v2 (PHP 8.2+ Compatibility)

I encountered a bug with the PHP SDK v2 where webhook calls were not being received.
After inspecting the SDK source code, I found a small issue that appears to be causing the problem.

I’ve submitted a pull request with a fix.

https://github.com/mindee/mindee-api-php/pull/175/changes/c4baa5459a741a24690145e3bdb13e257f596d90

Could you please review it?

Best regards,