- Rename common manifests to remove fedora prefix & ostree mention
- Directly include the common manifest in each variant manifest to
reduces the number of level of indirection for the manifests
Repos are overwritten by Pungi during composes in the Fedora infra and
Pungi currently only overwrites the leaf manifest.
See: https://pagure.io/releng/issue/11969
Reverts: 49db8be manifests: Move repos config to common manifest
Use a filtered comps group to add essential apps instead of manually
listing them in the manifest.
Also add gparted to the image as it needs privileges thus it can't run
as a Flatpak.
