Benchmarking

[tkoskela]

• Make tests and examples self-contained #346
• v4.2.0 releases of sopt and purify
• Spack recipe for sopt sopt: new package spack/spack#46837
• Spack recipe for purify [WIP] purify: new package spack/spack#46839
• ReFrame benchmark class Add purify radioastronomy benchmarks ukri-excalibur/excalibur-tests#337
• Test benchmarks on a cluster (Kathleen, CSD3, Cosma?)
• Debug MPI implementation
• Develop ONNX benchmark