[BUGFIX] Authentication service respects deleted-flag

[BUGFIX] Authentication service respects deleted-flag

Avoids impossible logins due to wrong mappings to old
(deleted) users with the same username as a valid one.

Resolves: #78378
Releases: master

Change-Id: I74b09b036fdd264861509e236f62683b81ba7075
Reviewed-on: https://review.typo3.org/50333
Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Reviewed-by: Mathias Brodala <mbrodala@pagemachine.de>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Jan Helke <typo3@helke.de>
Tested-by: Jan Helke <typo3@helke.de>