Update to artist credit handling

src/provider.rs

@@ -45,6 +45,9 @@ pub struct RecordingDetails {
     pub releases: Vec<ReleaseRef>,
     pub duration_ms: Option<u64>,
     pub genres: Vec<String>,
+    /// Non-featuring collaborators beyond the primary artist.
+    #[serde(default)]
+    pub secondary_artists: Vec<(String, String)>,
 }
 
 /// An artist match from a search query.