test: use shape_collection ontology declaration in lib imports test

Co-authored-by: aider (openai/gpt-5) <aider@aider.chat>

Author: gtfierro

tests/unit/api/test_model_manifest_endpoint.py

@@ -24,8 +24,8 @@ def test_post_model_manifest_with_library_ids_sets_imports(client, building_moti
     # Setup
     model = Model.create(name="urn:my_model_ids")
     lib = Library.create("lib_ids")
-    db_lib = building_motif.table_connection.get_db_library(lib.id)
-    db_lib.shape_collection.graph_name = "urn:test:lib_ids_sc"
+    sc = lib.get_shape_collection()
+    sc.graph.add((URIRef("urn:test:lib_ids_sc"), RDF.type, OWL.Ontology))
     building_motif.session.commit()
 
     # Act