[BUGFIX] Return empty array when user can't be found

FrontendUserRepository::fetchUserInformationByEmail now returns
empty array when there is no user with given email.

Resolves: #92601
Releases: master, 10.4, 9.5
Change-Id: Iad1d862de9e7c59879b4cfebdf15bc0d8e7fde55
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/66174


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>