Update pyyaml requirement from >=5.4.1 to >=6.0.3

Updates the requirements on [pyyaml](https://github.com/yaml/pyyaml) to permit the latest version.
- [Release notes](https://github.com/yaml/pyyaml/releases)
- [Changelog](https://github.com/yaml/pyyaml/blob/6.0.3/CHANGES)
- [Commits](https://github.com/yaml/pyyaml/compare/5.4.1...6.0.3)

---
updated-dependencies:
- dependency-name: pyyaml
  dependency-version: 6.0.3
  dependency-type: direct:production
...

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