Update K8s versions tested in E2E

[dfarrell07]

Add Kubernetes 1.26 and 1.28, remove end-of-life 1.22-1.25.

Add K8s 1.21, the oldest working version for Service Discovery.

Per discussions, only test ends of supported K8s version range. Don't
test versions in the middle of the range to avoid GHA runs that don't
add useful coverage.

[submariner-bot]

🤖 Created branch: z_pr1445/dfarrell07/k8s_128
🚀 Full E2E won't run until the "ready-to-test" label is applied. I will add it automatically once the PR has 2 approvals, or you can add it manually.

[dfarrell07]

Go Unit Tests failed, re-running.

[dfarrell07]

Go Unit Tests failed, re-running.

Passing now

[github-actions]

This pull request has been automatically marked as stale because it has not had recent activity. It will be closed if no further
activity occurs. Thank you for your contributions.

[tpantelis]

The E2E for K8s 1.21 where we change the backing pods fails. dig returns duplicate IPs which doesn't affect verification of discovered IPs b/c we check for string containment but it does affect the case where we expect no IPs. I think doing #1322 should alleviate this issue. It seems the behavior of EndpointSlices in 1.21 is a bit different that later versions.

[tpantelis]

The E2E for K8s 1.21 where we change the backing pods fails. dig returns duplicate IPs which doesn't affect verification of discovered IPs b/c we check for string containment but it does affect the case where we expect no IPs. I think doing #1322 should alleviate this issue. It seems the behavior of EndpointSlices in 1.21 is a bit different that later versions.

It actually turned out to be a bug in the production code. #1457 fixes it.

[submariner-bot]

🤖 Closed branches: [z_pr1445/dfarrell07/k8s_128]