[TASK] Rework nightly test run to execute less tests

The current nightly run simply takes too long, we need to cut
down the sheer number of tests we run. The current setup
aims to execute a small subset of all tests on each DBMS and
Php version, but in total every test is run in each composer stage
at least once.

Resolves: #91058
Releases: master, 9.5
Change-Id: I94fc6627f5da0cc6f36cf789ef8aa227d73d8daa
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/64152


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Markus Klein <markus.klein@typo3.org>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Reviewed-by: Markus Klein <markus.klein@typo3.org>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>