chore(deps-dev): bump @guardian/cdk from 61.3.1 to 61.8.1

Bumps [@guardian/cdk](https://github.com/guardian/cdk) from 61.3.1 to 61.8.1.
- [Release notes](https://github.com/guardian/cdk/releases)
- [Changelog](https://github.com/guardian/cdk/blob/main/CHANGELOG.md)
- [Commits](guardian/cdk@v61.3.1...v61.8.1)

---
updated-dependencies:
- dependency-name: "@guardian/cdk"
  dependency-version: 61.8.1
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]