zypper correctly identifies that "openblas-common-devel" replaces "openblas-devel", in the order of operations "openblas-devel" is deleted after installation of "openblas-common-devel".
I deleted "openblas-devel" using "rpm -e --nodeps openblas-devel" in a seperate terminal, then continued the installation of "openblas-common-devel" in "zypper dup" with "retry", and ignored the error message regarding the deletion of "openblas-devel" in zypper later.
zypper used to execute the deletion of packages as first order of action with "zypper dup", I am not sure why this is not the case anymore.
Kind regards
Berthold