fix: php 8.3 deprecated get_class method call without argument

[AmooAti]

Hi,

In this PR, I replaced get_class with self:class due to new deprecations in PHP 8.3, which you can read about it [here](https://wiki.php.net/rfc/deprecate_functions_with_overloaded_signatures#:~:text=has%20been%20closed.-,get_class()%20and%20get_parent_class(),-get_class()%20currently)

Since PHP 8.3 is still an RC version, Many things, like upgrading composer packages, need to be done to be compatible with PHP 8.3, but this is a code issue and can be solved right now.

[google-cla[bot]]

Thanks for your pull request! It looks like this may be your first contribution to a Google open source project. Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

View this failed invocation of the CLA check for more information.

For the most up to date status, view the checks section at the bottom of the pull request.

[ldebrouwer]

Just chiming in that this is blocking my team from upgrading our production systems to PHP 8.3 as well.

[bshaffer]

I'm not sure why the tests aren't running for this.

[bshaffer]

Unfortunately we are frozen until January 2nd, so we can't release this fix until then. You cau use dev-main in the meantime at your own risk

[parallels999]

Ok thanks, that will be very helpful 👍