Reduce the number of tests skipped in CI

[RobinPicard]

We currently skip many tests in the CI. We always have a good reason for it (depends on external API, requires unavailable hardware...), but it leads to a situation in which we may let many errors go unnotice. Another issue is that we exclude the files in question from coverage check, so we may have weak coverage for those files when we do run the tests for them.

We should explore options to reduce the number of tests that are skipped. We could for instance have (useful) mocking of external services or try to have tests run in several different environments for hardware issues.