[BUGFIX] Remove old grunt-copy dependency

Resolves: #78403
Releases: master
Change-Id: I55ec9f662cd7ddd827f1f46ab9c1664aac22a5b6
Reviewed-on: https://review.typo3.org/50342


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Stefan Bürk <stefan.buerk@impactmedia.de>
Tested-by: Stefan Bürk <stefan.buerk@impactmedia.de>
Reviewed-by: Patricia Tiedemann <pixelaeffchen@googlemail.com>
Tested-by: Patricia Tiedemann <pixelaeffchen@googlemail.com>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>