Drupal 10 compatibility

Hi @esolitos

I have added patch file for above MR, please review.

There was a similar issue with support for guzzle 7 on geocoder ( https://www.drupal.org/project/geocoder/issues/3283651 ✨ Drupal 10 compatibility: changing php-http/guzzle6-adapter dependency into php-http/guzzle7-adapter RTBC )
It's difficult to keep the full compatibility with Drupal 9 & 10 - even though guzzle 7 is also allowed on D9 now ( https://www.drupal.org/project/drupal/issues/3225966 → ), drupal/core-recommended is locked on guzzle 6, so it may cause some dependency problems.
As suggested in the description, adding a new 5.x branch seems like the best way to go.

I just fixed as much as I could. Fixed the tests and a lot of codestyle errors.

Not ready yet. The composer.json requires php-http/guzzle7-adapter (for compatibility with D10 core requirements), but zaporylie/vipps:^2 requires php-http/guzzle6-adapter

zaporylie/vipps doesn't require php-http/guzzle6-adapter

Agreed. My mistake