Update internal dependencies and change code accordingly

[davidjgoss]

🤔 What's changed?

• Bump gherkin-utils to get rid of vulnerable transitive dependency on [email protected]
• Bump html-formatter and tweak code to simplify and remove redundant package (see Default to built-in CSS and JS files html-formatter#344)

⚡️ What's your motivation?

Fixes #2457.

🏷️ 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.

---

This text was originally generated from a template, then edited by hand. You can modify the template here.

[coveralls]

coverage: 97.732% (-0.001%) from 97.733%
when pulling 87b7a38 on cuke-dependencies-jan25
into cc6c89e on main.