[TASK] Migrate Doctrine DBAL fetchAll() to fetchAllAssociative()

Since TYPO3 uses the \PDO::FETCH_ASSOC fetch mode
by default, fetchAll() is the equivalent for fetchAllAssociative()
which is the new API for Doctrine 3. In order to
move towards the new Doctrine DBAL 3.x API,
this change migrates all fetchAll() calls
to fetchAllAssociative() or fetchFirstColumn().

Resolves: #94618
Releases: master
Change-Id: I2ab4db871d0b65ad07e629b54bb79b1c3b411005
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/70016


Tested-by: core-ci <typo3@b13.com>
Tested-by: Oliver Bartsch <bo@cedev.de>
Tested-by: Georg Ringer <georg.ringer@gmail.com>
Reviewed-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>