[php-src] Issue #8438: HashTableIterators of empty hashtables are not poisoned upon free

Issue: https://github.com/php/php-src/issues/8438 Author: bwoebi ### Description Using the zend_hash_iterators_* API, non-empty arrays are properly marked as poisoned in the HashTableIterator entries. However there is an edge case: if nNumUsed == 0, then the zend_hash_iterators_remove call is skipped in zend_hash_destroy and zend_array_destroy. Thus, we either should: a) fix this by always calling the removal ... or b) completely remove the auto-removal on destruction and leave it the extension authors responsibility to clear the iterators From the perspective of the code in php-src there is no need to have the auto-removal on free, as every iterating thing holds a reference to it. ### PHP Version master ### Operating System _No response_