CI caching

[cc-a]

The testing ci workflow is still quite slow. The caching for pre-commit doesn't seem to be working. The cache gets saved but never loaded so this could be investigated to improve things. Could also look into caching the docker images for the services so these don't need to be re-downloaded each time. Looks like there is experimental support for this - https://docs.docker.com/build/cache/backends/gha/