The LoadTests Go Combine Flink Batch job is flaky

[github-actions]

The LoadTests Go Combine Flink Batch is failing over 50% of the time
Please visit https://github.com/apache/beam/actions/workflows/beam_LoadTests_Go_Combine_Flink_Batch.yml?query=is%3Afailure+branch%3Amaster to see the logs.

[damondouglas]

After investigating, my hypothesis is that the workflow's attempt to restart the flink runner is failing this test. This is suggested by the gRPC failure to call the endpoint.

[github-actions]

Reopening since the workflow is still flaky