[TASK] Replace usage of legacy PageRepository class

In two places, TYPO3\CMS\Frontend\Page\PageRepository had been
used instead of TYPO3\CMS\Core\Domain\Repository\PageRepository.

As this will eventually fail in the future, the wrong usage has
been fixed.

Releases: master
Resolves: #89901
Change-Id: I5799bcb93486e3c8aa4a71fe4ad03cfce34948d1
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/62586


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Tested-by: Daniel Goerz <daniel.goerz@posteo.de>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Reviewed-by: Daniel Goerz <daniel.goerz@posteo.de>