[TASK] Run test lintPhp on all CPU cores

Use all available CPUs with `Build/Scripts/runTests.sh -s lintPhp`.

Note podman CI is configured with a cpu-share to prevent starving
other jobs when one is greedy, so this change is ok with CI, too.

Resolves: #103864
Related: #103851
Related: #102385
Releases: main, 12.4, 11.5
Change-Id: I1cb7079f119677b36d6f4004398ae24bd8c5d284
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/84286


Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Stefan Bürk <stefan@buerk.tech>
Tested-by: Stefan Bürk <stefan@buerk.tech>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>