[DOCS] Extend docs of DeleteUploads finisher

Releases: master, 9.5
Resolves: #89416
Change-Id: I4565d846bb86077c3e03534416f3047e2f7f0ce6
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/61997


Tested-by: Björn Jacob <bjoern.jacob@tritum.de>
Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Daniel Goerz <daniel.goerz@posteo.de>
Reviewed-by: Björn Jacob <bjoern.jacob@tritum.de>
Reviewed-by: Daniel Goerz <daniel.goerz@posteo.de>