[!!!][TASK] Removed deprecated flushByTag hook

Resolves: #101021
Related: #100963
Related: #99592
Releases: main
Change-Id: I79cf6f1c786e472ea2b8b4a0b62669c4b6eadf54
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/79305


Tested-by: core-ci <typo3@b13.com>
Tested-by: Benni Mack <benni@typo3.org>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Benni Mack <benni@typo3.org>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>