[TASK] Add note concerning breaking changes after v11.0

Resolves: #95274
Releases: master
Change-Id: If60f410ff1e1ed6a8f52e30df32900a4be73ad27
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/71124


Tested-by: Oliver Bartsch <bo@cedev.de>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Oliver Hader <oliver.hader@typo3.org>
Reviewed-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Oliver Hader <oliver.hader@typo3.org>