Upgrade: [dependabot] - bump @aws-sdk/util-dynamodb

Bumps [@aws-sdk/util-dynamodb](https://github.com/aws/aws-sdk-js-v3/tree/HEAD/packages/util-dynamodb) from 3.994.0 to 3.996.1.
- [Release notes](https://github.com/aws/aws-sdk-js-v3/releases)
- [Commits](https://github.com/aws/aws-sdk-js-v3/commits/HEAD/packages/util-dynamodb)

---
updated-dependencies:
- dependency-name: "@aws-sdk/util-dynamodb"
  dependency-version: 3.996.1
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]