chiaki: fix license information (GPLv3+ -> AGPLv3)

This was changed by upstream in the 2.0 release and missed when we
update the nixpkgs package.

pkgs/games/chiaki/default.nix

···
   meta = with lib; {
     homepage = "https://git.sr.ht/~thestr4ng3r/chiaki";
     description = "Free and Open Source PlayStation Remote Play Client";
-    license = licenses.gpl3Plus;
+    license = licenses.agpl3Only;
     maintainers = with maintainers; [ delroth ];
     platforms = platforms.all;
   };