The source project of this merge request has been removed.
Add Qt 6.2 based Linux CI image
I was originally hoping to share most of the non-Qt parts with the 5.15 image, but they diverge pretty much in the first line already by using different repos, so it's largely a copy for now.
This does aggressively exclude anything pulling in Qt5-based dependencies. We can probably relax this, but for now this should help avoiding any undesired Qt major version mixing while we are still sorting out the basics.