[BUGFIX] Do not show empty dates of system news

If the creation date of a system news is cleared by an editor, the
rendered news must skip the date.

Resolves: #94576
Releases: master, 10.4
Change-Id: I93958ba0e858960dba4b99c0123cedce7dba5539
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/69908


Tested-by: Nikita Hovratov <nikita.h@live.de>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Guido Schmechel <guido.schmechel@brandung.de>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Torben Hansen <derhansen@gmail.com>
Tested-by: Georg Ringer <georg.ringer@gmail.com>
Reviewed-by: Nikita Hovratov <nikita.h@live.de>
Reviewed-by: Guido Schmechel <guido.schmechel@brandung.de>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Torben Hansen <derhansen@gmail.com>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>