Fix Ubuntu ppc64el dependency repo generation

[viniciusferrao]

Summary

• Add Ubuntu Noble to build-ubunturepo so core and dependency apt repositories can publish Noble metadata.
• Add a DISTS override for targeted local repo validation, for example DISTS="jammy noble".
• Wire the existing -r option for dependency repo builds so a binary xCAT-genesis-base RPM can be converted and staged as a .deb before reprepro creates the apt repository.

Notes

The ppc64el dependency packages were not missing as binaries: goconserver, grub2-xcat, ipmitool-xcat, and xcat-genesis-base-ppc64 already exist in the Ubuntu dependency package set used by older suites. The failure for newer Ubuntu ppc64el installs is caused by missing Jammy/Noble dependency repo metadata/publication.

Validation

• bash -n build-ubunturepo
• git diff --check
• Native ppc64le Ubuntu 22.04 container: generated local xcat-dep apt repositories for jammy and noble; both binary-ppc64el/Packages files contained goconserver, grub2-xcat, ipmitool-xcat, and xcat-genesis-base-ppc64.
• Native ppc64le Ubuntu 22.04 container: apt-get -s install xcat succeeded using public Jammy core-snap plus the locally generated Jammy xcat-dep repository.
• Native ppc64le Ubuntu 22.04 container: build-ubunturepo -d -r <binary xCAT-genesis-base-ppc64 rpm> converted and published xcat-genesis-base-ppc64_..._all.deb into Jammy binary-ppc64el metadata.