[BUGFIX] Use DBAL Restrictions for index_config queries

The IndexSearch repository calls $TSFE->sys_page->enableFields
for queries on index_config which has very static information
(deleted/hidden) which the default restriction container handles.

Changing this code was simply forgotton to migrate to the
restriction container.

Resolves: #81188
Releases: master, 8.7
Change-Id: I159b4c2cf898e97b0e92fd2a57bcd30de0806146
Reviewed-on: https://review.typo3.org/52755


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Reviewed-by: Jan Helke <typo3@helke.de>
Tested-by: Jan Helke <typo3@helke.de>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>