build(deps): bump aws-lambda-powertools from 2.19.0 to 2.21.0

Bumps [aws-lambda-powertools](https://github.com/aws-powertools/powertools-lambda-python) from 2.19.0 to 2.21.0.
- [Release notes](https://github.com/aws-powertools/powertools-lambda-python/releases)
- [Changelog](https://github.com/aws-powertools/powertools-lambda-python/blob/develop/CHANGELOG.md)
- [Commits](aws-powertools/powertools-lambda-python@v2.19.0...v2.21.0)

---
updated-dependencies:
- dependency-name: aws-lambda-powertools
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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