[TASK] Bring back datetime related acceptance tests for FormEngine

The test have been disabled due to flakiness, let's give them
another chance to prove themselves valuable.

Resolves: #79730
Releases: master, 9.5
Change-Id: I8f0f64971438effb4b8baa62819d44c2920742de
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/63937


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Benni Mack <benni@typo3.org>
Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Reviewed-by: Benni Mack <benni@typo3.org>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>