While Mageia does not yet produce DeltaRPMs, it would never make
sense to fetch them for building ARM images, so we just turn it off
pre-emptively to simplify things for the future.
Some mirrors have issues with ranged fetching of files, which is a
critical aspect of fetching zchunk-based repodata. In order to
to improve the reliability of fetching repodata and packages, disable
this.
With self-contained configuration, the repository definitions
will be predictable based on the target architecture and avoid
leaking anything from the host.
