YaspFixedSizePartioner broken after !607
The updates in !607 (merged) break downstream code
error: cannot declare variable ‘lb’ to be of abstract type ‘Dune::YaspFixedSizePartitioner<1>’
4 169 | Dune::YaspFixedSizePartitioner<dim> lb(partitioning);
5 | ^~
/dune/modules/dune-grid/dune/grid/yaspgrid/partitioning.hh:237:84: error: type ‘Dune::YLoadBalanceForward<1>’ is not a direct base of ‘Dune::YaspFixedSizePartitioner<1>’
21 237 | YLoadBalanceForward<d>(std::make_unique<Yasp::FixedSizePartitioning<d>>(dims))
22 | ^