Take over changes from Android templates to AppImage template
Apply similar changes as in !49 (merged) adapted for building an AppImage.
Additionally, the locale is explicitly set to en_US.UTF-8. The system locale of the Docker image is set to this locale, but it doesn't seem to be used for the job session.
The changes where successfully tested with Kate: https://invent.kde.org/utilities/kate/-/jobs/564265