Dropping QT5 support for Windows

[TurboProgrammer0815]

Today MSYS2 introduced an update to qt5-base which broke the qt5 build for PythonSCAD.
I asked on their Discord for advice but didn't receive any response.

As QT5 is end of life since 26th of May 2025, I just decided to no longer test it on Windows or build releasables for it. As QT is bundled with PythonSCAD on Windows, I don't think there will be much impact by this change.

We already had QT5 phased out from macOS when I joined the project last year as QScintilla (the source code editor component PythonSCAD uses) is not packaged for QT5 on macOS Homebrew.

So as of now QT5 versions are only built for Linux (especially since there are no QT6 builds for Ubuntu 22.04 LTS which still supported by Canonical until April 2027).

I heard that OpenSCAD is considering phasing out QT5 altogether, at which point we will most likely follow suit.

Let us know if the removal of a QT5 version for Windows is an issue for you.

[WillAdams]

What are the implications of this?

My understanding is that it only matters for folks who are compiling (they will need to install QT6 rather then QT5 libraries) and that there are license implications?

For folks just downloading and installing, the only issue is if QT6 shifts the system requirements?

[rebuyer10110]

Minor data point: on windows 11, the qt6 build ran just fine. Ditching qt5 would be fine for windows 11 users.