[NETWORK_PER_BUILD] reproduce the unix socket errors seen on the Shared Runners

Summary

During the roll out of the feature flag NETWORK_PER_BUILD, edge cases were observed on the Shared Runners, the feature was since disabled on all the Shared Runners until the root cause is understood.

Plan

Since the feature is still enabled on the Private runners, we can carry out reproduction tests there.

Next Steps

• Attempt reproducing the error on the Private runners.
• Attempt changing the feature flag via .gitlab-ci.yml
• Attempt having a SSOT for the errors seen by the users from an external tool, eg. Grafana/Thanos/Kibana.
• Gather results and write up findings.
• Decide on next steps.