[TASK] Remove "max" attribute from datetime fields in TCA

It's not required to limit the maxlength of datetime fields
by TCA anymore, as the used DateTimePicker already validates
the values.

Releases: master
Resolves: #66593
Change-Id: Ib2ab070c907e790c7b23a4cacf3cd11aa5e219fc
Reviewed-on: http://review.typo3.org/38925


Reviewed-by: Mathias Schreiber <mathias.schreiber@wmdb.de>
Tested-by: Mathias Schreiber <mathias.schreiber@wmdb.de>
Reviewed-by: Michael Oehlhof <typo3@oehlhof.de>
Tested-by: Michael Oehlhof <typo3@oehlhof.de>
Reviewed-by: Markus Klein <klein.t3@reelworx.at>
Tested-by: Markus Klein <klein.t3@reelworx.at>