Add support for Node.js 25.x

[davidjgoss]

🤔 What's changed?

Add testing for Node.js 25.x in CI, and add to the enginesTested for user messaging.

🏷️ What kind of change is this?

• 🏦 Refactoring/debt/DX (improvement to code design, tooling, etc. without changing behaviour)

📋 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.

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[coveralls]

coverage: 97.808%. remained the same
when pulling 8e231f0 on node-25
into c3b2401 on main.