feat: refresh Node.js versions support

[davidjgoss]

🤔 What's changed?

Remove support for Node.js 14, 16 and 19. Add explicit support for 20.

⚡️ What's your motivation?

Fixes #2325

🏷️ What kind of change is this?

• 🏦 Refactoring/debt/DX (improvement to code design, tooling, documentation etc. without changing behaviour)
• 💥 Breaking change (incompatible changes to the API)

📋 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: 98.458%. remained the same when pulling 22e658f on feat/drop-nodejs-14-16 into 89ec3b6 on main.