Fix unit test

Author: WaVEV

tests/indexes_/test_checks.py

@@ -142,7 +142,7 @@ class Meta:
                 checks.Error(
                     "VectorSearchIndex requires the same number of similarities "
                     "and vector fields; expected 1 similarity but got 2.",
-                    id="django_mongodb_backend.indexes.VectorSearchIndex.E004",
+                    id="django_mongodb_backend.indexes.VectorSearchIndex.E005",
                     obj=Article,
                 ),
             ],