Revert "don't block on ofborg"

[wolfgangwalther]

This reverts commit a4ff10d.

OfBorg for Linux runs reliably today, so we should make use of its results.

[wolfgangwalther]

Rebased, but I'd like to run this one on staging first, once we have access to that.

[philiptaron]

I haven't reviewed this since (in my experience) I trust / look at posted nixpkgs-review logs much more than I look at ofBorg... and the uncertain delay with which it comes in is pretty frustrating.

[wolfgangwalther]

Well, this would still ignore darwin. And the two linux systems are pretty reliable and fast in my recent memory.

(Edit: With the exception of nixosTests on aarch64-linux)

[philiptaron]

I'll leave the matter to you and @MattSturgeon. We can always go back to the current regime if it's frustrating, I suppose.

[wolfgangwalther]

I converted this to draft, because ofborg is currently not working at all and it has been unstable in the last months. Not ofborg itself, but it is not well maintained and its infra seems to be affected by other things going on at the same time (IIUC related to new hydra stuff).