Address deprecation warning in Unit Tests

[michael-lloyd-morris]

🤔 What's changed?

Fixing a deprecation warning in the unit tests.

> mocha 'src/**/*_spec.ts'

  ........(node:38244) [DEP0147] DeprecationWarning: In future versions of Node.js, fs.rmdir(path, { recursive: true }) will be removed. Use fs.rm(path, { recursive: true }) instead
(Use `node --trace-deprecation ...` to show where the warning was created)
...........................................................................................................
  ...................................................................................................................
  ................................................................................................

  326 passing (4s)

⚡️ What's your motivation?

Bugfix - well, a potential bug when the Node team finally follows up on the deprecation.

🏷️ What kind of change is this?

• :bug: Bug fix (non-breaking change which fixes a defect)

📋 Checklist:

• [x] 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.

[coveralls]

Coverage: 98.561% (+0.0006%) from 98.561% when pulling 3b94338f4e3fb5a22c1867e027204f2a4fea1524 on michael-lloyd-morris:fixDeprecation into 627030d4d657b7efc19b1343d3d77d77c774139e on cucumber:main.