[TASK] Avoid handling L=OUT in LoginController

Logout should run through LogoutController.
Avoid this widely unknown code in LoginController
since it does not belong there and does not log.

Resolves: #104744
Related: #104742
Releases: main
Change-Id: Id535d620d4e72daf48ff05da6253de296df9f752
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/85789


Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Simon Praetorius <simon@praetorius.me>
Tested-by: core-ci <typo3@b13.com>
Reviewed-by: Simon Praetorius <simon@praetorius.me>
Reviewed-by: Andreas Kienast <a.fernandez@scripting-base.de>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Andreas Kienast <a.fernandez@scripting-base.de>