Investigate and fix intermittent conformance test failures

[sjberman]

Seemingly after R33 was added, we're seeing a few intermittent conformance test failures. We need to investigate to see what the issue might be. The failing tests may be different each time, and it's only ever 1 or 2 of them.

Sample run failure: https://github.com/nginxinc/nginx-gateway-fabric/actions/runs/11941430523/job/33286439349

Acceptance

• diagnose the failure
• fix the issue

[sjberman]

Closing for now. The error still occurs very randomly, but I'm not able to reproduce it to investigate the issue. It's probably related to an issue with R33 connecting to the upstream endpoint for usage reporting. A rerun seems to fix it. While annoying, the failure hasn't been happening frequently enough to cause serious delays.