Error when pushing to the CAS server: "Name resolution failure"

Summary

I got the following backtrace when pushing to the CAS server: https://gitlab.com/freedesktop-sdk/freedesktop-sdk/-/jobs/107204101

Steps to reproduce

• I have only see this one once; I will update this if I see it again

What is the expected correct behavior?

• Handle this gracefully

• BuildStream version affected: buildstream 1.2.3 on both server and client