Support php-http so that customers can use their own http client

[MIchaelMainer]

I'm having the same issue. Even worse, in my case, this requires me to update the major version of Symfony, which I can't do for now.
Can you allow ^6.0 || ^7.0? As seen in #311, there's no changes in the usage of Guzzle.
Or better, migrate to php-http and let us choose the HTTP client of our choice

Originally posted by @Mika56 in #324 (comment)
AB#6323