Fix deprecation: use SagaMetadata.CreateMany instead of SagaMetadataCollection.Initialize

Co-authored-by: danielmarbach <174258+danielmarbach@users.noreply.github.com>

Author: Copilot

src/NServiceBus.Storage.MongoDB.Tests/Sagas/SagaTestsConfiguration.cs

@@ -27,8 +27,7 @@ public SagaMetadataCollection SagaMetadataCollection
 
             var sagaTypes = Assembly.GetExecutingAssembly().GetTypes().Where(t =>
                 typeof(Saga).IsAssignableFrom(t) || typeof(IFinder).IsAssignableFrom(t)).ToArray();
-            field = new SagaMetadataCollection();
-            field.Initialize(sagaTypes);
+            field = SagaMetadata.CreateMany(sagaTypes);
 
             return field;
         }