This PR adds a few scikit-hep python packages to ensure that they are pre-installed and available for benchmarks (without pulling them in when the requirements.txt is called).
hepunits~=2.3.2
hist~=2.6.1
histoprint~=2.4.0
particle~=0.23.0
vector~=0.8.5Note: The version of vector will be updated to the latest 1.4.0, but that will take a bit longer.