[DOCS] Make the reason why noopener was removed more visible

Releases: main, 12.4
Resolves: #103262
Change-Id: I30f4c1c7fd0f27b1712bbead42ceea6bf5f5e0f5
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/83107


Tested-by: core-ci <typo3@b13.com>
Tested-by: Stefan Bürk <stefan@buerk.tech>
Reviewed-by: Stefan Bürk <stefan@buerk.tech>