The rule trailing_comma_in_multiline is added to the PHP CS fixer
configuration.

This reduces possible merge conflicts in the future.

The commands to apply the rules over the code base was

./bin/php-cs-fixer fix \
    --path-mode intersection \
    --config=Build/php-cs-fixer.php \
    typo3/sysext

And then:
./bin/php-cs-fixer fix --config=Build/php-cs-fixer.php

Resolves: #94553
Releases: master
Change-Id: I0ebbfa9edbbcde19aaeb44219a71f2f093ab705e
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/69825
Tested-by: core-ci <typo3@b13.com>
Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Benni Mack <benni@typo3.org>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Reviewed-by: Benni Mack <benni@typo3.org>