[BUGFIX] Prevent deprecation notice in InputLinkElement

Add missing typecast to prevent deprecation notice.

Resolves: #102396
Releases: 11.5
Change-Id: I49f22bac872b2485cb282ce26121a06e08f87810
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/81802


Reviewed-by: Nikita Hovratov <nikita.h@live.de>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Nikita Hovratov <nikita.h@live.de>