obsidian: use magick instead of convert

Author: w-lfchen

pkgs/by-name/ob/obsidian/package.nix

@@ -61,7 +61,7 @@ let
         -t $out/share/applications/
       for size in 16 24 32 48 64 128 256 512; do
         mkdir -p $out/share/icons/hicolor/"$size"x"$size"/apps
-        convert -background none -resize "$size"x"$size" ${icon} $out/share/icons/hicolor/"$size"x"$size"/apps/obsidian.png
+        magick ${icon} -background none -resize "$size"x"$size" $out/share/icons/hicolor/"$size"x"$size"/apps/obsidian.png
       done
       runHook postInstall
     '';