[BUGFIX] Fix regeneration of autoload files in testing context

In testing context and in non composer mode, the additional class loading
information should be regenerated for each test run.

The code for that never worked and is now fixed with this change.

Resolves: #70482
Releases: master
Change-Id: Ia8e23d9c4409e6e5ce17c6520458913634888913
Reviewed-on: http://review.typo3.org/43904


Reviewed-by: Nicole Cordes <typo3@cordes.co>
Tested-by: Nicole Cordes <typo3@cordes.co>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>