[TASK] Remove deprecated code

Still some deprecated code is used in version extension.

Change-Id: Id593398a5905d92278a7a39d413dbf9755a9a8b9
Related: #46950
Releases: 6.1
Reviewed-on: https://review.typo3.org/19612
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn