I just reproduced the issue and reviewed the files and packages: The issue is related to the rpmfusion packages:
This means, the problem lies in a conflict between
libheif-freeworld: if any package wants to install or update one of these two as hard or weak dependency WHILE the other is already installed OR both are already installed installed, the install will break because of the conflict.
Please file a bug against the component at rpmfusion bugzilla: ReportingBugs - RPM Fusion
I have not yet used the bugzilla of rpmfusion: if you can add multiple components, add both
libheif-freeworld. If not, focus at least on one, or if you have the time, file against both.
However, although being a bit probabilistic, you could also open a ticket on our Fedora bugzilla (https://bugzilla.redhat.com/) against the component
libheif because any Fedora that has rpmfusion enabled (which are a lot) will have a broken installation/update once installing/updating the
libheif package from our own default repositories. So the relation to our own
libheif package is that our package “officially” contains the rpmfusion packages as weak dependencies.
Further, if you do that, please cross-link all pages so that everyone who ends up on one page also gets the links to the other: rpmfusion bugzilla ticket(s), fedora bugzilla ticket, this ask.fp topic.
Until the issue is solved, I suggest to do
dnf update with
dnf update --exclude=libheif* to exclude libheif* from the update this time. However, with each update, check out first
dnf clean all; dnf update before excluding the package, so that you find out when the issue is solved: exclusion is not a long term solution. I do not think the
clean all will be necessary, but it will ensure that any cache or metadata that contains the error/conflict will be replaced by the fixed.