getSetInfo() artwork_url always null

[BDT-4248]

Apparently each time doing scdl.getSetInfo() will always get this:

{
    artwork_url: null,
    created_at: '2022-11-03T01:10:39Z',
    description: null,
    duration: 379115,
    embeddable_by: 'all',
    genre: '',
    id: 1521503137,
    kind: 'playlist',
    label_name: null,
    last_modified: '2022-11-03T01:10:39Z',
    license: 'all-rights-reserved',
    likes_count: 7,
    managed_by_feeds: false,
    permalink: 'natasha-bedingfield-unwritten',
    permalink_url: 'https://soundcloud.com/matthibbertmusic/sets/natasha-bedingfield-unwritten',
    public: true,
    purchase_title: null,
    purchase_url: null,
    release_date: null,
    reposts_count: 0,
    secret_token: null,
    sharing: 'public',
    tag_list: '',
    title: 'Natasha Bedingfield - Unwritten (Matt Hibbert Edit) (Filtered for SC, full vocal in DL)',
    ...
}

everything else is fine except for artwork_url, why is that??? it's very annoying to always get null for this when clearly playlists like this one has an artwork_url