PHP 8 Compatibility

Problem/Motivation

I tried to install degov as described in the "Getting started" guide but it can't be installed as degov still depends on PHP 7 which is deprecated for drupal (and not available on many webhosters anymore).

Steps to reproduce

Try to use
composer create-project degov/degov-project my_project_name/ --prefer-source --keep-vcs
in a PHP 8.1 environment.

Proposed resolution

Update this project's composer.json to follow the current recommended drupal standards and use PHP 8 compatible module versions.