hypnotix: Add missing circles-flags

This fixes the log spam of "Couldn't find flag
/usr/share/circle-flags-svg/xx.svg" and adds missing
icons to the location list.

pkgs/applications/video/hypnotix/default.nix

···
 , fetchFromGitHub
 , substituteAll
 , cinnamon
+, circle-flags
 , gettext
 , gobject-introspection
 , mpv
···
   postPatch = ''
     substituteInPlace usr/lib/hypnotix/hypnotix.py \
       --replace __DEB_VERSION__ ${version} \
+      --replace /usr/share/circle-flags-svg ${circle-flags}/share/circle-flags-svg \
       --replace /usr/share/hypnotix $out/share/hypnotix
   '';