Bazzite shows that terra-release is indeed installed
Assuming it is disabled (as happened in https://github.com/ublue-os/bazzite/issues/2580)
Interesting conflict; as these seem to be at odds with each other. I wonder what's up. If it's indeed disabled, then I would like to apologize for causing any confusion. FWIW, I may have been mislead by Terra's own documentation. I suppose it might be outdated.
Anyhow, perhaps we can undertake the steps to uninstall terra-release (even if it's not there) and (re)install it.
Uninstalling terra-release
If terra-release is layered^[You can check this with rpm-ostree status. If it is, you will find it after LayeredPackages:. If it's not, you should not evoke rpm-ostree uninstall terra-release, as it wouldn't get through anyways.], then we'd have to start with rpm-ostree uninstall terra-release. Afterwards, to delete the Terra repository, even if it's not even there^[If ls /etc/yum.repos.d/ | grep "terra" doesn't yield anything, then you may skip this. But evoking the command to delete something that's not there, isn't bad or anything.]: sudo rm -rf /etc/yum.repos.d/terra.repo
(Re)installing terra-release
To (re)install terra-release (as per its own instructions):
First evoke the following command:
curl -fsSL https://github.com/terrapkg/subatomic-repos/raw/main/terra.repo | pkexec tee /etc/yum.repos.d/terra.repo
And then, evoke this one: sudo rpm-ostree install terra-release . I'm unsure if sudo is required. Personally, first I'll do is without sudo. Only after it fails due to permissions will I do it with sudo.
A reboot is probably required for it to take effect. Hence, try evoking rpm-ostree install throne only after performing a reboot.