fix(fc2c-i): ruff I001 one-per-line import in test_artist_service

tests/test_artist_service.py

@@ -3,7 +3,13 @@ from datetime import UTC, datetime
 import pytest
 
 from backend.app.models import (
-    Artist, ImageProvenance, ImageRecord, Post, Source, Tag, TagKind,
+    Artist,
+    ImageProvenance,
+    ImageRecord,
+    Post,
+    Source,
+    Tag,
+    TagKind,
 )
 from backend.app.models.tag import image_tag
 from backend.app.services.artist_service import ArtistService