Update runtime to a supported version

[yakushabb]

Source: flathub/cn.navclub.ldbfx#3

This application relies on an old runtime that was marked as end-of-life (EOL) two years ago.

We are marking abandoned apps as EOL.

Please consider updating to a supported version.

Thanks.

LC_ALL=C flatpak remote-info flathub --system org.gnome.Platform//42
End-of-life: The GNOME 42 runtime is no longer supported as of March 21, 2023. 
Date: 2023-03-22 12:44:22 +0000