Don't scrobble media with zero duration

lib/music_library/scrobble_activity.ex

@@ -75,6 +75,14 @@ defmodule MusicLibrary.ScrobbleActivity do
   end
 
   def scrobble_medium(number, release_with_tracks, {:started_at, started_at}) do
+    medium_duration =
+      release_with_tracks.media
+      |> Enum.find(fn medium -> medium.number == number end)
+      |> Release.medium_duration()
+
+    if medium_duration == 0 do
+      {:error, :no_duration}
+    else
       session_key = Secrets.get!("last_fm_session_key").value
 
       medium =
@@ -87,6 +95,7 @@ defmodule MusicLibrary.ScrobbleActivity do
 
       LastFm.scrobble(scrobbles, session_key)
     end
+  end
 
   defp to_scrobbles(tracks, release_with_tracks, started_at) do
     tracks