Richards test do not converge

It seems that after !2574 (merged), some richards tests don't converge anymore, causing all pipelines to fail: https://git.iws.uni-stuttgart.de/dumux-repositories/dumux/-/pipelines/3789

I only checked one output log and saw that test_richards_benchmark_infiltration_tpfa fails due to timeout with poor newton convergence. There may be more tests affected.

In the MR I see that at the latest stage at least, there was no pipeline triggered. Did you test locally before merge @heck, @timok ?