[BUGFIX] Fix binding to `this` in event API

This patch ensures `this` is correctly bound to the triggering element
which is mandatory for event delegation.

Resolves: #90618
Releases: master
Change-Id: Icddcce55bbd62c452ac419d120ef9550b91cb306
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/63526


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Benni Mack <benni@typo3.org>
Reviewed-by: Benni Mack <benni@typo3.org>