dependabot-npm(deps-dev): bump @getkist/action-nunjucks (#220)

Bumps [@getkist/action-nunjucks](https://github.com/getkist/kist-action-nunjucks) from 2.0.14 to 2.0.28.
- [Commits](https://github.com/getkist/kist-action-nunjucks/commits)

---
updated-dependencies:
- dependency-name: "@getkist/action-nunjucks"
  dependency-version: 2.0.28
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]