[Feature] Print KubeRay logs in Buildkite runner when tests fail

[LeoLiao123]

Why are these changes needed?

See #2652

Related issue number

Closes #2652

Manual tests

I set the timeout to 1 second locally using the following command to make the test fail, and observed the logs to see if there was any output :

go test -timeout 1s -v ./test/e2e || (kubectl logs --tail -1 -l app.kubernetes.io/name=kuberay && exit 1) >> ~/data/kuberay-operator.log

kuberay-operator.log :

{"level":"info","ts":"2024-12-27T06:14:03.982Z","logger":"setup","msg":"Loaded feature gates","featureGates":{"RayClusterStatusConditions":true}}
{"level":"info","ts":"2024-12-27T06:14:03.983Z","logger":"setup","msg":"Flag watchNamespace is not set. Watch custom resources in all namespaces."}
{"level":"info","ts":"2024-12-27T06:14:03.983Z","logger":"setup","msg":"Setup manager"}
{"level":"info","ts":"2024-12-27T06:14:04.185Z","logger":"setup","msg":"starting manager"}
{"level":"info","ts":"2024-12-27T06:14:04.185Z","logger":"controller-runtime.metrics","msg":"Starting metrics server"}
{"level":"info","ts":"2024-12-27T06:14:04.185Z","logger":"controller-runtime.metrics","msg":"Serving metrics server","bindAddress":":8080","secure":false}
{"level":"info","ts":"2024-12-27T06:14:04.186Z","msg":"starting server","kind":"health probe","addr":"[::]:8082"}
{"level":"info","ts":"2024-12-27T06:14:04.387Z","msg":"attempting to acquire leader lease default/ray-operator-leader..."}
{"level":"info","ts":"2024-12-27T06:14:21.213Z","msg":"successfully acquired lease default/ray-operator-leader"}
...

And after setting it properly and passing the test using the following command, I observed the log output:

go test -timeout 30m -v ./test/e2e || (kubectl logs --tail -1 -l app.kubernetes.io/name=kuberay && exit 1) >> ~/data/kuberay-operator.log

kuberay-operator.log :

(empty)

Therefore, it can be confirmed that the logs are printed only when the test fails.

Checks

• I've made sure the tests are passing.
• Testing Strategy
  • Unit tests
  • Manual tests
  • This PR is not tested :(

[LeoLiao123]

@kevin85421 , @MortalHappiness PTAL.