Fix: Handle missing PipelineVersion in Kubernetes API mode

[Goku2099]

Fixes an issue where GetPipelineV1 fails if a PipelineVersion is not found.

The current implementation assumes that a "latest" PipelineVersion always exists and returns an error if it is missing ("PipelineVersion: Latest not found"). This causes the Kubeflow UI to fail when accessing pipelines created in Kubernetes API mode.

This PR updates the behavior to:

• Gracefully handle missing PipelineVersion
• Return the pipeline without failing when the version is not found
• Preserve existing behavior for other error cases

This ensures compatibility between v1beta1 API expectations and v2beta1 CRD-based pipelines.

Fixes #13216

[google-oss-prow]

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[google-oss-prow]

Hi @Goku2099. Thanks for your PR.

I'm waiting for a kubeflow member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

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[Copilot]

Pull request overview

This PR attempts to fix an issue where the Kubeflow Pipelines backend fails when accessing pipelines in Kubernetes API (CRD) mode when a PipelineVersion is not found. The fix modifies GetPipelineV1 to gracefully handle missing PipelineVersion by checking if the error message contains "not found", then setting pipelineVersion to nil and continuing instead of returning an error.

Changes:

• Modified GetPipelineV1 to catch "not found" errors from getLatestPipelineVersion and allow nil pipelineVersion instead of failing
• Continues to return an error for other error cases