Add Support for PHP 8.3

[osrecio]

• There is an issue ticket which accompanies my PR: .
• I have followed the guidelines for contributing.
• I have checked that there aren't other open pull requests for the same issue ticket.
• I have formatted my code with the PSR-2 coding style before submitting my PR.

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I have read the contribution guidelines and am targeting the branch 2.x:
Because this is a Feature which is not Backwards Compatible.

Changelog entry:
Added support for PHP 8.3
Short description of your work as explained by: Keep A Changelog.

[mischabraam]

Nice, thanks.
I can merge this, but... I'm actually not supporting version 2. Version 3.x (which I will release soon) already supports PHP 8.3. To release version 3 I actually can use some help with testing it.