Can we enable CI for legacy systems?

[Clemens Lang]

Hi,

GitHub Actions supports self-hosted runners, see
  https://docs.github.com/en/actions/hosting-your-own-runners/about-self-hosted-runners

I personally wouldn't have a problem with optional CI steps running on
other people's machines, as long as that's for pull requests and we
don't use the results anyhere but to post status information to GitHub.

Stricly speaking, the hosted VMs from Azure we're currently using are
"other people's machines", too.

-- 
Clemens