[TASK] typo3/testing-framework now flushes runtime caches

Unit test tearDown() now always calls
GeneralUtility::flushInternalRuntimeCaches() so most explicit
calls in unit tests can be removed.

composer require --dev typo3/testing-framework:~4.8.2

Resolves: #85948
Related: #85946
Releases: master, 8.7
Change-Id: I798047a06c3265404383540cacbd40d9719e7bfe
Reviewed-on: https://review.typo3.org/58008


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>