Prepare for API change in JUnit.

[mdealer]

Improve compatibility in advance to jenkinsci/junit-plugin#625

Fixes
java.lang.NoSuchMethodError: 'java.util.List hudson.tasks.junit.ClassResult.getChildren()'

Testing done

Unit Tests run locally

Submitter checklist

• Make sure you are opening from a topic/feature/bugfix branch (right side) and not your main branch!
• Ensure that the pull request title represents the desired changelog entry
• Please describe what you did
• Link to relevant issues in GitHub or Jira
• Link to relevant pull requests, esp. upstream and downstream changes
• Ensure you have provided tests - that demonstrates feature works or fixes the issue

[jglick]

Did you actually try this in PCT, which compiles a plugin’s tests against its declared dependencies but then runs them against its updated dependencies? I suspect you would still get an error.

[timja]

I'm trying in a min the update was just merged: jenkinsci/bom#3395 (could have done pre-merge but looked safe to me)

[timja]

Running here: https://github.com/jenkinsci/bom/pull/3394/checks?check_run_id=27805511895

[jglick]

I guess it does not much matter, since this is released first, and it is only test code.

[jglick]

⇒ jenkinsci/junit-plugin#625 (comment)