[TASK] Update PHPStan to 1.6.3

The new version finds some new possible bugs.

Used commands:

> composer require --dev phpstan/phpstan:^1.6.3
> Build/Scripts/runTests.sh -s phpstanGenerateBaseline

Resolves: #97508
Releases: main, 11.5
Change-Id: I7a813c4f12258aad96b99cec3feb93ee10d55bcf
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/74482


Tested-by: core-ci <typo3@b13.com>
Tested-by: Stefan Bürk <stefan@buerk.tech>
Reviewed-by: Stefan Bürk <stefan@buerk.tech>