[php-src] Issue #20914: Internal enums can be cloned

Issue: https://github.com/php/php-src/issues/20914
Author: arnaud-lb

### Description

The following code:

```php
<?php

var_dump(clone(ZendTestIntEnum::Foo) === ZendTestIntEnum::Foo);
```

Resulted in this output:
```
bool(false)
```

But I expected this output instead:
```
Uncaught Error: Trying to clone an uncloneable object of class ZendTestIntEnum
```

This is because we don't override the default object handlers in `zend_register_internal_enum()`.

### PHP Version

```plain
PHP 8.3
```

### Operating System

_No response_