Requiring `guzzlehttp/guzzle` causes roadblocks

[jgangso]

I want to once again bring up the issue already discussed in #1337 about guzzlehttp/guzzle.

While I understood the reasoning for requiring guzzle was more about making life easier for the developers, it actually will potentially become a roadblock for some.

For instance, we have a Concrete CMS based project where even the newest version (9.1.3) requires guzzle ^6.3. Elasticsearch 7.x is EOL anytime soon and we should upgrade to ES8. However, the ES client package versions 8.x require guzzle ^7.0 which conflicts with the requirement from Concrete CMS.

This leaves us in a poor position where we either have to run a EOL service or make own workarounds which sort of counter-works everything Composer stands for.

I agree with @ruudk that guzzle rather belongs to suggests than require, and will emphasise that there are obvious disadvantages of the latter.