[TASK] Remove skipped test in DisjunctionValidatorTest

The functionality guarded by the test does not apply anymore.
After the test has been skipped since a long time already,
it is safe to just remove it.

Change-Id: I7757b57e7f7424d2631f67b736d927f525e01f0b
Resolves: #85625
Releases: master
Reviewed-on: https://review.typo3.org/57664


Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>