TYPO3 V10 

Changes that should happen once we drop TYPO3 v10.

Remove fetching cached page stage from body from tests 

We have different assertions based on TYPO3 version, due to how TYPO3 exposes the info. We can remove the condition with its content once we drop v10.

Remove condition for page not found handling 

The AbstractController->trigger404() method has a condition to handle 404 differently for TYPO3 v10. The condition can be removed.