v0.4 madgraph4gpu bmk - BUG FIX: use "--gpus all" and "--nv" only for GPU benchmarks
v0.4 madgraph4gpu bmk - BUG FIX: use "--gpus all" and "--nv" only for GPU benchmarks
The fix was necessary when I tried to create an improved (faster) LHCb 2021 benchmark, which does not use the GPU