Truncate verbose CauseOfBlockage messages in queue

[MarkEWaite]

Test "Truncate verbose CauseOfBlockage messages in queue"

Do not merge

Testing pull request:

• [JENKINS-45927] Truncate verbose CauseOfBlockage messages in queue jenkins#11298

Testing done

None. Rely on ci.jenkins.io

Submitter checklist

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• Ensure that the pull request title represents the desired changelog entry
• Please describe what you did
• Link to relevant pull requests, esp. upstream and downstream changes
• Ensure you have provided tests that demonstrate the feature works or the issue is fixed

[MarkEWaite]

Failing test passes for me locally. Running again to see if the test is a flake. Test seems unrelated to the Jenkins in core.

[MarkEWaite]

Tests pass. Closing