[TASK] Fix runTests.sh -u

Add typo3/ infix as images were otherwise tried
to be updated from ghcr.io/core-testing-*
instead of ghcr.io/typo3/core-testing-*.

Resolves: #101885
Releases: main, 12.4, 11.5
Change-Id: I4a866971158916264d21435377d43d2b843bf16d
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/80911


Tested-by: core-ci <typo3@b13.com>
Tested-by: Stefan Bürk <stefan@buerk.tech>
Reviewed-by: Stefan Bürk <stefan@buerk.tech>