In order to build the Linux version of the application we use the `ubuntu:20.04` Docker image where we install the Qt 5.15.2 provided by [aqt](https://github.com/miurahr/aqtinstall), linuxdeployqt provided by https://github.com/probonopd/linuxdeployqt and other dependencies (go, cmake, gcc etc.). We're using Ubuntu 20.04 to ensure glibc compatibility with the oldest still-supported LTS release and to comply with linuxdeployqt requirements.