You can contribute to KDE with non-C++ code

Not everything made by KDE uses C++. This is probably obvious to some people, but it's worth mentioning nevertheless.

And I don't mean this as just well duh, KDE uses QtQuick which is written with C++ and QML". I also don't mean this as well duh, Qt has a lot of bindings to other languages". I mean explicitly KDE has tools written primarily in certain languages and specialized formats".

Thiago Sueto

If you ever wanted to contribute to KDE but weren't sure if your preferred programming language or tools were relevant, this is a great blog post detailing how you can contribute if you are familiar with any of the following: Python, Ruby, Perl, Containerfile/Docker/Podman, HTML/SCSS/JavaScript, Web Assembly, Flatpak/Snap, CMake, Java, and Rust. A complex, large project like KDE needs people with a wide variety of skills, so it's definitely not just C++.

An excellent place to start.