[Cleanup] Kill comment

src/sand-wedge.cc

@@ -210,7 +210,6 @@ int main(int argc, char *argv[]) {
         Grid>;
     ZeroNonlinearity<LocalVector, LocalMatrix> zeroNonlinearity;
 
-    // TODO: clean up once generic lambdas arrive
     auto const solveLinearProblem = [&](
         Dune::BitSetVector<dims> const &_dirichletNodes, Matrix const &_matrix,
         Vector const &_rhs, Vector &_x, EnergyNorm<Matrix, Vector> const &_norm,