[headercheck] Link targets against Dumux::Dumux library
What this MR does / why does DuMux need it:
From Dune release 2.10 headercheck targets also need to be linked manually against libraries after buildsystem changes in DUNE.
Edited by Timo Koch
What this MR does / why does DuMux need it:
From Dune release 2.10 headercheck targets also need to be linked manually against libraries after buildsystem changes in DUNE.