Investigate presubmit samples test failures

[gemmahou]

Checklist

• I did not find a related open issue.
• I did not find a solution in the troubleshooting guide: (https://cloud.google.com/config-connector/docs/troubleshooting)
• If this issue is time-sensitive, I have submitted a corresponding issue with GCP support.

Bug Description

The presubmit samples failed after PR#2583, and that blocks the open PRs.

The two failed tests are samples/regional-forwarding-rule-vpc-psc and samples/computeserviceattachment(flaky).

Checking the logs, the forwarding rule is a dependency of the service attachment, and the deletion of the forwarding rule is blocked because there is no network (the network was deleted before). It seems like we need to handle the deletion ordering in the direct controller. It's strange that the presubmit on the original PR passed. I had a temporary fix: #2614, but the two tests are still failing, so I think there's a deeper issue (deletion ordering, etc.).

Additional Diagnostic Information

job: https://github.com/GoogleCloudPlatform/k8s-config-connector/actions/runs/10681623224/job/29605684721

Kubernetes Cluster Version

N/A

Config Connector Version

N/A

Config Connector Mode

namespaced mode (default)

Log Output

No response

Steps to reproduce the issue

N/A

YAML snippets

No response

[ziyue-101]

Just provide a thought.

the presubmit on the original PR passed

• Maybe the PR has an old base and that is why it passed.
• Could be a race condition between two controllers/reconcilers.