Migrate to GNOME 46 runtime

[matytyma]

Flatpak warning:

Info: runtime org.gnome.Platform branch 44 is end-of-life, with reason:
The GNOME 44 runtime is no longer supported as of March 20, 2024.

[yakushabb]

Fixed on Flathub.

flathub/io.github.lainsce.DotMatrix#2