bug#44835: gnu/ci.go: Embeds build path, breaking reproducible builds

[Mathieu Othacehe]

Hey,

> … but I don’t think we can assume that the checkout is in the
> ‘%load-path’ when this code is executed.  WDYT, Mathieu?

Cuirass happens to add checkouts to the %load-path just before loading
this file.

I tested your path, it works fine. I think it is acceptable as this (gnu
ci) interface needs a big rework anyway.

I can apply your patch if it's ok for you.

Thanks,

Mathieu