PHP 8.x fixes #229
Description
Fixes we should make for PHP 8.2+ compatibility, but currently cannot:
- Remove the
ReturnTypeWillChangeattribute introduced here: https://github.com/dxw/whippet/pull/228/files#diff-82ad1f5c575998eae8e759ec6322e3d4a99b56a45bf60b675a64be1a5bf87045R28. This is currently required for Kahlan compatibility.