Bump aws/aws-sdk-php from 3.297.3 to 3.368.0 in /php/example_code/rds

Bumps [aws/aws-sdk-php](https://github.com/aws/aws-sdk-php) from 3.297.3 to 3.368.0.
- [Release notes](https://github.com/aws/aws-sdk-php/releases)
- [Commits](aws/aws-sdk-php@3.297.3...3.368.0)

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

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Author: dependabot[bot]