Improve CI coverage for more systems like MacOS and Windows

[kfriedberger]

Our Gitlab-Ci and our AppVeyor CI are good, run well and cover most internal use cases.
However, those CIs have limited resources and do not provide more architectures, such as ARM64 for both, Windows and MacOS.
We could take a look at alternatives, without costs for open-source projects.

[kfriedberger]

As a first step, we improved the support for Linux with additional configurations for arm64 architecture in #442 .