bastet: Add platforms

I had initially forgotten to add this.

+1
+1
pkgs/games/bastet/default.nix
··· 24 24 homepage = http://fph.altervista.org/prog/bastet.html; 25 25 license = licenses.gpl3; 26 26 maintainers = [ maintainers.dezgeg ]; 27 + platforms = platforms.linux; 27 28 }; 28 29 }