Why do you have a repo with "Centos7" in its name installed on a CentOS 8 system? That does not sound correct. I would suggest that you look to see which file in /etc/yum.repos.d/ defines that repo, then query which package owns that file using rpm -qf /etc/yum.repos.d/$file.repo (obviously changing $repo to the filename in question!). If a package owns it then yum remove that package as it's not the correct one for your system.
Also, CentOS Linux 8 went EOL at the end of 2021 and there will be no more updates to it. If you are running CentOS Linux 8 then you need to convert your system to one of the new rebuilds (see my Sig below) or you need to convert it to the new "beta-like" CentOS Stream 8. CentOS Linux 8 is EOL and should not be used any morel
Both Alma and Rocky have conversion scripts that will go from CentOS Linux 8 to their distros. Both are CentOS Linux replacements and aim to be bug for bug compatible with RHEL 8. There is also CentOS Stream 8 which is more... beta.