Run the macOS docker-related tests on the CI
At the moment, the macOS tests are using the dummy provider. Because it seems possible to run Docker Desktop on the macOS runners, we could do so and run the docker-related tests as well on ARM64 and Intel.
Comments mention that "it takes around 10mn" to install, so we might want to cache this somehow.
After some more investigation, it doesn't seem to be doable, because Nested Virtualization is not currently possible on the github runners, as mentioned here:
Nested-virtualization and Metal Performance Shaders (MPS) are not supported due to the limitation of Apple's Virtualization Framework. — source
Some users report they have been able to run colima, but we've had issues with colima ourselves, and it's currently not a supported container runtime for Dangerzone.
The last option I see here is to rely on external dedicated action runners, like this.
Resolved as part of #1225, which will be soon pushed to main.