Sped up artist enrichment at least somewhat

tests/integration.rs

@@ -89,6 +89,12 @@ impl MetadataProvider for MockProvider {
     ) -> DataResult<Vec<shanty_tag::provider::ReleaseGroupEntry>> {
         Ok(vec![])
     }
+
+    async fn resolve_release_from_group(&self, release_group_mbid: &str) -> DataResult<String> {
+        Err(shanty_data::DataError::Other(format!(
+            "no releases for release-group {release_group_mbid}"
+        )))
+    }
 }
 
 async fn test_db() -> Database {