Linker failuer with current `dune-solvers`

dune-contact fails to build with a linker error on the CI system with a current version of dune-solvers:

dune/solvers/solvers/loopsolver.cc:61: undefined reference to `Dune::Solvers::Criterion::header() const'

I think dune-sovlers recently added a library that needs to be linked. I'll look at it later today.