build(deps-dev): bump knip from 6.18.0 to 6.20.0

Bumps [knip](https://github.com/webpro-nl/knip/tree/HEAD/packages/knip) from 6.18.0 to 6.20.0.
- [Release notes](https://github.com/webpro-nl/knip/releases)
- [Commits](https://github.com/webpro-nl/knip/commits/knip@6.20.0/packages/knip)

---
updated-dependencies:
- dependency-name: knip
  dependency-version: 6.20.0
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]