Trouble updating from fc36 to fc38

Try this way, assuming the relevant RPMs are already downloaded:

sudo rpm --rebuilddb
sudo rpm --nodeps -e fedora-release-workstation
sudo rpm --nodeps -e fedora-release-identity-workstation
sudo rpm --nodeps -e fedora-release-common
sudo rpm --force --nodeps -i fedora-release-common-38-*.noarch.rpm
sudo rpm --force --nodeps -i fedora-release-identity-workstation-38-*.noarch.rpm
sudo rpm --force --nodeps -i fedora-release-workstation-38-*.noarch.rpm
sudo ln -f -r -s /usr/lib/os-release /etc
rpm -q -a fedora-release\*
rpm -V -a fedora-release\*