Deploy self-hosted runner for test suite CI #147
Description
Description
With #90, the system tests can now be run in parallel. This can significantly speed up their execution, but because running the tests in parallel requires Docker, this speed-up is negated in CI by the time spent building the Docker image. Even when caching the image, loading and storing it from cache takes too long.
This problem could be solved by (https://docs.github.com/en/actions/hosting-your-own-runners) using a self-hosted runner, since then the Docker image can be stored in persistent memory. Such a self-hosted runner would also have other advantages, such as not having to reinstall the test suite dependencies for each workflow run. Therefore, the sequential system tests and performance tests would also run faster in CI.