CentOS 7.9 mirrorlist fix

sed -i "s/mirror.centos.org/vault.centos.org/g" /etc/yum.repos.d/*.repo
sed -i "s/^#.*baseurl=http/baseurl=http/g" /etc/yum.repos.d/*.repo
sed -i "s/^mirrorlist=http/#mirrorlist=http/g" /etc/yum.repos.d/*.repo

Source: https://x.com/usaamahahmed1/status/1819931166394274263?s=46