[TASK] Deprecate PageRepository->getPathFromRootline

The method is unused and does not belong in the PageRepository
if ever needed again.

Resolves: #77405
Releases: master
Change-Id: I6090afac564ac92b14f5277145fff1845417934f
Reviewed-on: https://review.typo3.org/49375


Tested-by: Bamboo TYPO3com <info@typo3.com>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>