Support php-http/guzzle7-adapter

I am using this package for a Laravel project 7.x, When upgrading to Laravel 8, it requires `guzzlehttp/guzzle` 7.x while `php-http/guzzle6-adapter` requires `guzzlehttp/guzzle` 6.x. Do we have any plans to support `guzzlehttp/guzzle` 7.x for this package?

https://github.com/php-http/guzzle6-adapter/pull/72
https://github.com/php-http/discovery/pull/189