fix: exit early when we have no artists

rave/src/utils.rs

@@ -155,6 +155,11 @@ fn format_artist(
         actual_artists.extend(album_artists.into_iter().map(|v| (4, v))); // Prioritize album artists over track artists
     }
 
+    if actual_artists.is_empty() {
+        // return early. No artists found
+        return None;
+    }
+
     let mut actual_artists = actual_artists
         .into_iter()
         .flat_map(|(prio, v)| {