Returning null from Bar::__debugInfo() is deprecated (PHP 8.5)

[staabm]

see

• php/php-src@3dc962b
• https://3v4l.org/aQTPl#v8.5.3

[VincentLanglet]

Given the fact that something like
https://phpstan.org/r/3302c240-489f-4a5d-a114-6d453c553525
is reported as an error in PHP, while it's just a deprecation on PHP (https://3v4l.org/OXoo7#v8.5.3)

I wonder if PHPStan should just report the error in the core and not just in deprecation-rules.