Found with bin/find-unneeded-includes
Only removal proposals are dealt with here
A bit of fallout management was necessary as well
find-unneeded-includes gave no proposals for chart2/inc

Change-Id: Id382586f575cf45da758da453df9340b28e9ddd0
Reviewed-on: https://gerrit.libreoffice.org/54778Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>