I tried to upgrade from F30 to F32 without doing updates first, and I got:
gnome-software[2045]: not handling error download-failed for action
refine: failed to refine distro upgrade: Failed to download gpg key for
repo 'fedora': Curl error (37): Couldn't read a file:// file for
file:///etc/pki/rpm-gpg/RPM-GPG-KEY-fedora-32-x86_64 [Couldn't open file
/etc/pki/rpm-gpg/RPM-GPG-KEY-fedora-32-x86_64]
And I am thinking... well, if we could have gnome-software (maybe even
dnf) to update fedora-gpg-keys.noarch before trying to upgrade to the
next version, it would make it more likely to succeed.