openblas is using %{?_isa} in BuildRequires which is prohibited by Packaging Guidelines: https://fedoraproject.org/wiki/Packaging:Guidelines#BuildRequires_and_.25.7B_isa.7D. Please fix it ASAP.
Fixed in rawhide. The arched BRs were only used if the package was built with --with system_lapack, so there's no change to the binaries.