Web requests get super-slow after running a while

This is somewhat masked by nginx-caching proxy, but nonetheless very noticeable and grating. 😖

This is caused by dnsname-plugin inside rootless-cni-infra container. Contents of /run/containers/cni/dnsname/ci-deploy/addnhosts reveal multiple old and invalid entries for dns. Those will cause a seemingly random amount of delay, as dnsnames will be tried by proxy in different order each time.