Get macos CIs running again

[mvieth]

It seems like OpenNI has not been installed for longer than the problems with depends_on java exist (and just fixing these dependency problems does not result in OpenNI being installed again). I suggest we open an issue to investigate those problems.

[larshg]

Since https://github.com/brewsci/homebrew-science is legacy and doesnt get any new PRs accepted, we might as well just remove it?
I'm not sure if we can get in another way, though?

[mvieth]

Since https://github.com/brewsci/homebrew-science is legacy and doesnt get any new PRs accepted, we might as well just remove it?

Maybe they are going to make an exception for that specific PR, since right now apparently no project can be installed from that repository.

I'm not sure if we can get in another way, though?

No idea. My intention with this PR is to get the macos CIs running again as soon as possible. Then we can work on getting OpenNI installed again in a next step.

[larshg]

Yeah, lets keep it. If they manage to get it working, openni would be installed again. But until its fixed, the core libraries are still getting installed 😄