[TASK] Use new acceptance test splitter script

The script to split acceptance tests into chunks has been
rewritten in typo3/testing-framework and is used in pre-merge
and nightly plan. It should lead to a more fair split into
single jobs so they end up with similar runtimes again.
One test file is additionally split into three to allow
better distribution.

composer update typo3/testing-framework

Resolves: #85618
Releases: master
Change-Id: Ic65c29c5d0e4813d3953d1e70bd0c746df2b8ff4
Reviewed-on: https://review.typo3.org/57658


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>