Supporting Qt 6 - What's needed?

[wmayer]

That’s excellent – it doesn’t exist for Qt6, and removing it from the tests in SetupQt.cmake has that file under 50 lines now, which I feel pretty good about. Of course, now I have to change our CI setup! It turns out it was using WebKit when it compiled, so this PR is failing CI. I should be able to get to that later today.

I just realized an issue with removing QtWebkit. On MSYS2 a package Qt5WebEngineWidgets doesn’t exist because the code currently doesn’t compile and the only alternative is QtWebkit. For now I have to disable the Web module.

msys2 PyQtWebEngine