Remove deprecated display-info-goal

[StefanSpieker]

Fixes #702

Remove deprecated <goal>display-info</goal> from enforcer
According to maven-enforcer-plugin this is deprecated. And in plugins we see it somewhat double currently:

• 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

[basil]

Same change needs to be made to https://github.com/jenkinsci/pom/blob/abfb275d865d045fbd1db334d7af9d62a3ac66fa/pom.xml#L571 for consistency.