Convert to centos-stream-release
- Move all repo files, GPG keys, and dnf vars to centos-repos
- Move rootfs-expand script to its own package
- Switch to noarch
- Upgrade path from centos-release/centos-release-stream/centos-repos
- Upgrade path from centos-linux-release
- Upgrade path from centos-userland-release
- Set os-release variables to appropriate bugzilla values