[TASK] Disable ext:introduction installer ac test

Core v10 compatible releases of ext:introduction and
ext:bootstrap_package will take time until the other day.
To not disable all install related tests, the
ext:introduction related ac tests are skipped for master
for the time being.

Resolves: #87168
Releases: master
Change-Id: I498a9962beca9b9d5e87f7c19fd02ea72db961ac
Reviewed-on: https://review.typo3.org/59162


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>