probe-desktop: CI/macOS: investigate problems

[hellais]

The probe-desktop github actions CI gets stuck very often leading to it running for hours and then eventually timing out.

I think we should disable the build on macOS until we figure out what is going on with that build and make it work more reliably.

[hellais]

For the moment I just disabled the macOS builds: ooni/probe-desktop@ae4e785

More work on actually investigating and fixing the issue is needed.

[hellais]

@majakomel do you think this is still needed? If so we should probably add more details to the ticket on what are the next steps about it.

I am un-assigning myself and bumping down the priority.