[TASK] Update to PHPStan 1.8.8

This update finds new problems and gets rid of some
false positives.

Run commands:

> composer req --dev phpstan/phpstan:^1.8.8
> ./Build/Scripts/runTests.sh -s phpstanGenerateBaseline

Resolves: #98541
Releases: main, 11.5
Change-Id: Idff8e6f7f9baa700a79ec0e823aee14f0fb63efb
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/76013


Tested-by: core-ci <typo3@b13.com>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>