Build [extra] packages with checkdepends from [multilib]

The clean chroot set up when using pkgctl build against a package from [extra] does not include/enable the [multilib] repo.
This makes pkgctl build fail in the specific case of an [extra] package that "check-depends" on a [multilib] one (for instance lutris which has a check dependency on wine), as the needed multilib package isn't found.

The current workaround is to use pkgctl build --repo multilib to force the inclusion/usage of the [multilib] repo within the chroot, despite the package being released in [extra] afterwards.

Obviously this is a very specific case, I assume there's not too many [extra] packages with check dependencies from [multilib].

I remain available if needed 🙂