[TASK] Remove dead code paths identified by PHPStan

According to PHPStan, these checks are all unnecessary.
Most of them appear to be type checks that have been
rendered unnecessary due later type additions. They
are therefore removed without replacement.

Used command:

> Build/Scripts/runTests.sh -s phpstanGenerateBaseline

Resolves: #97622
Releases: main, 11.5
Change-Id: I9aac41e98b22fcce55afb97f8aeaebe3209a8bfb
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/74782


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