Roll back service creation on error

ref #202

src/servala/core/models/service.py

@@ -663,6 +663,7 @@ class ServiceInstance(ServalaModelMixin, models.Model):
             return mark_safe(f"<ul>{error_items}</ul>")
 
     @classmethod
+    @transaction.atomic
     def create_instance(cls, name, organization, context, created_by, spec_data):
         # Ensure the namespace exists
         context.control_plane.get_or_create_namespace(organization)
@@ -710,7 +711,7 @@ class ServiceInstance(ServalaModelMixin, models.Model):
                 body=create_data,
             )
         except Exception as e:
-            instance.delete()
+            # Transaction will automatically roll back the instance creation
             if isinstance(e, ApiException):
                 try:
                     error_body = json.loads(e.body)