This project builds the official, unmodified, Qt Webkit source code for C++17 using GitHub actions runners.
Using curl to download and extract to /opt/qt5:
curl -L https://github.com/constructpm/qtwebkit-build/releases/download/v5.212.0-1/qtwebkit-d1c854e-cpp17-$PLATFORM-x64.tar.gz | sudo tar -xJC /opt
where $PLATFORM is ubuntu-18.04 or ubuntu-22.04.