Fix PHP 8.5 deprecations of chr() and array iterator

Problem/Motivation

new deprecations appeared after beta2

Steps to reproduce

- https://wiki.php.net/rfc/deprecations_php_8_5#deprecate_arrayobject_and_...
- https://wiki.php.net/rfc/deprecations_php_8_5#deprecate_passing_integers...

Proposed resolution

fix them

Remaining tasks

review/commit

User interface changes

Introduced terminology

API changes

Data model changes

Release notes snippet