build(deps-dev): bump cspell from 5.18.5 to 5.21.2

Bumps [cspell](https://github.com/streetsidesoftware/cspell) from 5.18.5 to 5.21.2.
- [Release notes](https://github.com/streetsidesoftware/cspell/releases)
- [Changelog](https://github.com/streetsidesoftware/cspell/blob/v5.21.2/CHANGELOG.md)
- [Commits](streetsidesoftware/cspell@v5.18.5...v5.21.2)

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

Signed-off-by: dependabot[bot] <[email protected]>