See https://en.opensuse.org/SDB:Zypper_troubleshooting, can you run:
ZYPP_LOGFILE=zypper-refresh-updates.log zypper remove amdgpu-dkms
And try to find the rpm command, if that does not work, add “ZYPP_FULLLOG=1”
When you have the rpm command, add -v to the command and run it stand-alone.