[TASK] Remove the comment "Test case" from test files

These comments don't add any value as the class under test can be easily
determined from the filename.

Executed commands:

> grep -Rn -E "^\s\*\sTest case(\sfor.*|\.)?$" --include="*Test\.php" \
typo3/sysext/ | awk -F':' '{print "sed -i \047" $2-1 "," $2+1 "d\047 " $1}' | sh

Some files with more comments needed manual adaption.

Resolves: #98956
Releases: main
Change-Id: Ia2fe96edda6ac26203bdfe8537a4d6e9d3e768c0
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/76332


Tested-by: core-ci <typo3@b13.com>
Tested-by: Chris Müller <typo3@krue.ml>
Tested-by: Oliver Klee <typo3-coding@oliverklee.de>
Tested-by: Georg Ringer <georg.ringer@gmail.com>
Reviewed-by: Chris Müller <typo3@krue.ml>
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>