[Archetype] Replace JUnit Jupiter with AssertJ

[mpkorstanje]

⚡️ What's your motivation?

As a JUnit Platform Engine, Cucumber does not need JUnit Jupiter. It was included as a dependency to allow users to use Assertions. This is better done with AssertJ.

🏷️ What kind of change is this?

• 📖 Documentation (improvements without changing code)

📋 Checklist:

• I agree to respect and uphold the Cucumber Community Code of Conduct
• I've changed the behaviour of the code
  • I have added/updated tests to cover my changes.
• My change requires a change to the documentation.
  • I have updated the documentation accordingly.
• Users should know about my change
  • I have added an entry to the "Unreleased" section of the CHANGELOG, linking to this pull request.