Behaviour changes
- Requires Guzzle 7.15.2 or higher. Guzzle 6 and Guzzle 7 versions below 7.15.2 have known security vulnerabilities, and Composer already blocks installing Guzzle 6 by default. PHP 7.4 is still supported. If you can't upgrade Guzzle yet, stay on v4.7.0. #698