configure apt's barbarian architectures for the cross build profile

The cross build profile indicates that we cannot execute host architecture binaries. It can be used to include additional dependencies that are needed to avoid running built tools. On the flip side, Multi-Arch:foreign packages usually contain things we want to run and that typically means that satisfying them from the host architecture will not work. While apt prefers satisfying dependencies on Multi-Arch:foreign packages from the build architecture, it occasionally does so anyway and when it does things usually go wrong. Configuring the host architecture as "barbarian" prevents this from happening.

Closes: #1071246