Hide niri/language widget if formatted string is empty

[Gskartwii]

I like to use the following configuration to completely hide the widget when the English keyboard layout is selected:

    "niri/language": {
      "format": "{}",
      "format-en": "",
      "format-us": "",
      "format-fi": "Finnish"
    },

The format_ member references the format configuration key. But if I were to set that to "", then the widget would be unconditionally hidden.