qt6ct doesn't show kvantum as an option

[martinkg]

When you have qt6ct and kvantum installed, what would usually happen is that qt6ct shows kvantum as an available option in the drop-down menu in the "appearance" tab to use to theme QT programs (the correct behavior that qt5ct shows).

Instead, qt6ct simply ignores that kvantum is an option.

Reproducible: Always

Steps to Reproduce:

1. install the "qt6ct" and kvantum "packages"
2. launch qt6ct
3. try to find the kvantum option in the drop down menu inside qt6ct's appearance tab.
   Actual Results:
   No kvantum option appeared in the dropdown menu.

Expected Results:
You should see the kvantum option in the dropdown menu.

I suspect that this bug is related specifically to qt6ct because kvantum can theme programs without problems if it's selected as one of the theming options inside KDE's appearance settings.

This problem is also present on Debian 12 and Ubuntu 23.10, if someone figures out a solution please tell the developers on charge of these packages in their respective distros to fix it.
With urgency!!! Ubuntu 24.04 LTS is around the corner.

Here is a link that displays the bug graphically, 1 picture is worth more than 1000 words: