[richards][test][benchmark] Use direct solver to increaes test robustness

5 jobs for !2775 with fix/test-richards-benchmark-robustness
latest detached
Status Name Job ID Coverage
  Trigger
passed full-dune-2.7-clang

passed full-dune-2.7-gcc

passed full-dune-master-gcc

passed minimal-dune-2.7-gcc

 
  Downstream Modules
passed trigger lecture