feat: Run tests on Windows & macOS in CI

[Wissididom]

Description

• Windows: Docker can only run Windows Containers, so the PubSub Server and httpbin needed to be run manually in the background. First I tried using the repository that was used inside the docker image of the ubuntu test workflow, but that wasn't easy and pajlada suggested using httpbin-rs. That just didn't have the $HOST/status/{code} endpoints, so I searched for alternatives and found httpbox, which I then used.
• macOS: Using Colima to make Docker work. Without it, I get Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?.
• macOS: Use beta macos-13 to make the C++20 code work.
• Ubuntu: Add --output-on-failure to the workflow to see where the problem is if a test fails. Initially done to find a problem during playing around with it, but I think I can be helpful for later, so I kept it.

Occasional Problem

• Sometimes the macOS Qt6 workflow fails with error Subprocess aborted at different cases but I don't know why that might be. For me, it was always fixed after re-running the workflow.

Thought

To not have to use Docker and Colima on macOS, I could build the pubsub server and the httpbox tool on macOS in background too I think, but that probably won't make a difference I think.

Closes #4780

[pajlada]

Some nitpicks for the macOS file - overall this looks good 👍

[pajlada]

This looks good from my perspective, I imagine the cache using the same as the build script should be ok - @Nerixyz is is double-checking before this is merged in

[Nerixyz]

LGTM 👍