build.opensuse.org's CentOS-8-Stream with old URLs

While the prjmeta of CentOS:CentOS-8 on build.opensuse.org had been adjusted to account for the decommissioning of mirror.centos.org URLs (replaced by vault), the same has not been done for CentOS:CentOS-8:Stream. Please consider updating these too. I would suggest to do a system-wide grep (e.g. /srv/obs/projects/*.xml) for mirror.centos.org URLs.