[Linux] remove usage of QT_QPA_FONTDIR
Summary
Since https://gitlab.lan.local/Sight/sight-deps/merge_requests/7, exporting QT_QPA_FONTDIR is useless.
This need to be deleted in build & install shell script templates.
Since https://gitlab.lan.local/Sight/sight-deps/merge_requests/7, exporting QT_QPA_FONTDIR is useless.
This need to be deleted in build & install shell script templates.