* Re-add changes from #147.

* Update drupal-versions matrix and use latest upstream.

* Try to make tests pass.

* Attempt D10 upgrade.

* Attempt D10 upgrade fixes.

* Expand symfony/finder requirement.

* Add composer-drupal-lenient to allow plugins section.

* Set php version to 8.1.

* Upgrade php version earlier and make submodules d10 compatible.

* Port changes from #148.

* Get dev version of search_api_solr for D10.

* Always test again latest version of search_api_solr.

* Try testing in 8.1.

* Fix indentation error in Robofile.