api: exit EventStream.Stream on first error

[schmichael]

Errors from Decode are non-recoverable and should cause Stream to return. Otherwise Stream will loop forever on EOF from Decode.

Fixes #27133

Repro: https://gist.github.com/schmichael/247a39bf36406c08c8a95fc8c85bd56a

Description

Testing & Reproduction steps

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[jrasell]

LGTM!

I think we will also need a changelog entry and backport labels.