The below appears at first to be a bad mirror DNS error, but if you've ruled that out you just need to clear your broken yum cache and things will be good.
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
* base: centos.01link.hk
* extras: centos.01link.hk
* updates: centos.01link.hk
http://mirror.worria.com/centos/7.8.2003/os/x86_64/repodata/repomd.xml: [Errno 14] HTTP Error 404 - Not Found
Trying other mirror.
To address this issue please refer to the below wiki article
If above article doesn't help to resolve this issue please use https://bugs.centos.org/.
Delete yum cache and it will be OK
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