Codecov is not run in forks

[schlunma]

Looks like Codecov is not run in forks, e.g., #3178. This might be problematic since it could allow pushing code without tests.

I didn't find a fix for this unfortunately after briefly searching the web.

[valeriupredoi]

Codecov is configured for PRs no matter what they are, the problem is the cov report is not getting uploaded for forks - we tried that quite a bit, in other issues and contacted - I forgot what GitHub org produces that bit of code, but I can look it up again. Leave it to me, I'll retry things around 🍺