Add async job to fetch artist image

lib/music_library/worker/fetch_artist_image.ex

@@ -0,0 +1,10 @@
+defmodule MusicLibrary.Worker.FetchArtistImage do
+  use Oban.Worker, queue: :default, max_attempts: 3
+
+  @impl Oban.Worker
+  def perform(%Oban.Job{args: %{"id" => artist_id}}) do
+    with {:ok, _artist_info} <- MusicLibrary.Artists.fetch_image(artist_id) do
+      :ok
+    end
+  end
+end