[BUGFIX] Remove obsolete node in import test data header xml

Resolves: #57045
Releases: 6.2
Change-Id: I439305e5143b3c51a03befc642caf66286264679
Reviewed-on: https://review.typo3.org/28496
Reviewed-by: Wouter Wolters
Tested-by: Wouter Wolters
Reviewed-by: Marc Bastian Heinrichs
Tested-by: Marc Bastian Heinrichs