Use Server eventKey for Server Action

[RMadsenG]

Fixes #322

The if statement in getLatestCommit compares the eventKey to fulfilled instead of merged. This is causing merge builds to checkout the latest commit of the source branch instead of the merge commit.

Updating the constant to the BB Server constant.

Testing done

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

[RMadsenG]

Hello,
Reading the documentation here: https://github.com/actions/labeler, it looks the the Pull Request Labeler is failing bc I raised this pull request from my own fork. Is there any way around this?
Thank You

[RMadsenG]

@julioc-p @cdelmonte-zg Can you please review this when you have time.
thanks

[cdelmonte-zg]

Thank you @RMadsenG , it will be in the next bugfix release