build(deps-dev): bump guzzlehttp/guzzle in /tests/integration

Bumps [guzzlehttp/guzzle](https://github.com/guzzle/guzzle) from 7.9.2 to 7.9.3.
- [Release notes](https://github.com/guzzle/guzzle/releases)
- [Changelog](https://github.com/guzzle/guzzle/blob/7.9/CHANGELOG.md)
- [Commits](guzzle/guzzle@7.9.2...7.9.3)

---
updated-dependencies:
- dependency-name: guzzlehttp/guzzle
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]