core24 ships Qt 6.4.2 and the tree needs 6.8, so neither stage-packages
nor a remote source build can provide Qt: the dump recipe now takes the
AppDir tree from build-qt-linux.yml (both arches) and the root
snapcraft.yaml plus its packaging/snap symlink are deleted. snap-slint
becomes snap-qt with the non-Qt runtime only.
cc
vicrodh