snap: Updated to Qt 6

[bjorn]

I couldn't find any documentation on getting this to work. Possibly helpful references:

• PacketSender snapcraft.yaml
• KDocker snapcraft.yaml
• QOwnNotes snapcraft.yaml (based on core22)
• Sweetfish snapcraft.yaml (using kde-neon-6)

[bjorn]

Builds, but doesn't work:

bjorn@thor:Downloads$ snap install tiled_amd64.snap/tiled_1.11.0_amd64.snap --dangerous
tiled 1.11.0 installed
bjorn@thor:Downloads$ snap run tiled
/snap/tiled/x2/usr/bin/tiled: error while loading shared libraries: libQt6Widgets.so.6: cannot open shared object file: No such file or directory

Might just be missing libqt6widgets6t64 from stage-packages.

[bjorn]

Urgh...

/snap/tiled/x3/usr/bin/tiled: error while loading shared libraries: libQt6OpenGLWidgets.so.6: cannot open shared object file: No such file or directory

[bjorn]

/snap/tiled/x1/usr/bin/tiled: error while loading shared libraries: libpxbackend-1.0.so: cannot open shared object file: No such file or directory

[bjorn]

Well, adding libproxy1v5 did not resolve the libpxbackend-1.0.so issue.