Bump aws/aws-sdk-php in /php/example_code/dynamodb/dynamodb_basics

Bumps [aws/aws-sdk-php](https://github.com/aws/aws-sdk-php) from 3.356.18 to 3.368.0.
- [Release notes](https://github.com/aws/aws-sdk-php/releases)
- [Commits](aws/aws-sdk-php@3.356.18...3.368.0)

---
updated-dependencies:
- dependency-name: aws/aws-sdk-php
  dependency-version: 3.368.0
  dependency-type: direct:production
...

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

Author: dependabot[bot]