Automatic merge from submit-queue (batch tested with PRs 59398, 59881). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Pipe error message from openapi/swaggerspec verify checks to stderr

**What this PR does / why we need it**:
This pipes the error messages from openapi and swagger spec verify jobs to stderr so they show up in junit reports.

**Release note**:
```release-note
NONE
```