dir: Remove superfluous flatpak_dir_ensure_repo()
dir: Remove superfluous flatpak_dir_ensure_repo()

This is no longer needed since a FlatpakRemoteState is passed in, which
ensures the repo exists. The similar call was already removed from
flatpak_dir_install().

flatpak/flatpak,flatpak/flatpak,flatpak/flatpak,flatpak/flatpak,flatpak/flatpak