[TASK] Fix deprecated things in sysnote

The extension sysnote uses deprecated methods in the repository and
the controller. This patch will adjust that.

Fixes: #45349
Releases: 6.1

Change-Id: I7270efb264b80eb852ad972e8a492c0941e83be2
Reviewed-on: https://review.typo3.org/18194
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn