QGIS plugin unit tests are broken on Github actions

[deltamarnix]

On main the ribasim qgis plugin tests are broken.

We are trying to fix them by calling the tests locally via pixi run qgis, instead of with the docker image.

[deltamarnix]

I'm giving up on this issue. @evetion or @Hofer-Julian , maybe you want to take over. I have set up everything so that it works locally on a windows machine. Once in a while I receive a fatal exception, but most of the time it works.

When running on github actions, I receive errors that it cannot find the display. I have now set up xvfb up front for linux, but the build is hanging. And the windows build is green, but it's 10 minutes for running the test, which is insane.

[deltamarnix]

Fixed by #943