feat: add several scikit-hep python packages

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~=0.8.5

Note: The version of vector will be updated to the latest 1.4.0, but that will take a bit longer.

spack-environment/packages.yaml

@@ -326,7 +326,7 @@ packages:
     - '@1.5.3'
   py-particle:
     require:
-    - '@0.24.0'
+    - '@0.23.0'
   py-pip:
     require:
     - any_of: ['@23.1.2', '@23.0']