Increase PHPStan level to 4
What does this MR do?
Increase PHPStan level to 4, fix issues preventing that
How confident are you it won't break things if deployed?
very
Links to related issues
How to test
Just check the linter logs are green once !1666 (merged) is merged and this got rebased ;-)
Checklist
-
no test needed -
no unrelated changes -
asked someone for a code review -
set a "for:" label to indicate who will be affected by this change -
use "state:" labels to track this MR's state until it was beta tested -
added an entry to CHANGELOG.md -
forDev No release notes needed -
No beta testing needed
Edited by Chris Oelmueller