A little remark from my side for user who are not used to openSUSE (yet) in terms of how to find out whether you actually need a vendor change because the package got removed from a repo:
run
zypper se -v [packagename]that shows you which packages are in which repository and whether they are installed or not. Note: there are only your aliases for the repos listed but that’s enough in that case.
if you run zypper se -v libdca0 it should show you just the main (OSS) repo but not packman as source. Which means it’s not there (anymore).