Support for newer Qt versions

[3vi1]

Is your feature request related to a problem?

My current Linux desktop is using Qt 6.7.3 and Ubuntu's begun pushing Qt 6.8 in their devel repos for 25.04. However, Cura seems to be hardcoded to use Qt/PyQt version 6.6.0. When using the AppImage or compiling from source, the resulting app is unusuable because of you will get an error about mismatching Qt versions as soon as you even try to register or sign in.

It can be made to work with newer versions, but you have to not only update the requirements.txt file manually, but remove the 6.6.0 libraries from your python virtual environment (and install the proper version) after letting conan do its thing because something it pulls down forces installing PyQt6 v6.6.0 instead of whatever you put in the requirements.

It seems to work fine with the later Qt/PyQt6 versions after doing this, as there's no significant differences like between PyQt5 & PyQt6.

Describe the solution you'd like

I'm not familiar with conan's capabilities, but it would be great if we could either detect the QT version or at least easily configure it at compile time so that we don't need to stash changes and go through a more convoluted build process to test the latest Git updates.

Describe alternatives you've considered

Alternatively, maybe their could be multiple git branches for the newer versions?

Affected users and/or printers

I believe this would greatly benefit more technical Linux users (i.e. the kind who actively test and contribute back to projects).

Additional information & file uploads

Thanks! I haven't had much time to play with Cura yet - but this is a really impressive project!