[TASK] Change visibility of PageRepository->init

[TASK] Change visibility of PageRepository->init

The init() method is now called implicitly within the constructor,
so the last part is to mark the method protected.

Resolves: #86338
Related: #85450
Releases: master
Change-Id: Ic4c49f1dfbc3d9cda2f9c2bfbbdf4de333d836c0
Reviewed-on: https://review.typo3.org/58343
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>