fixed other edge case

Author: Andrei Neagu

services/director-v2/src/simcore_service_director_v2/modules/dynamic_sidecar/scheduler/_core/_events_user_services.py

@@ -237,9 +237,9 @@ async def progress_create_containers(
     start_duration = (
         scheduler_data.dynamic_sidecar.instrumentation.elapsed_since_start_request()
     )
-    assert start_duration is not None  # nosec
-    get_instrumentation(app).dynamic_sidecar_metrics.start_time_duration.labels(
-        **get_metrics_labels(scheduler_data)
-    ).observe(start_duration)
+    if start_duration is not None:
+        get_instrumentation(app).dynamic_sidecar_metrics.start_time_duration.labels(
+            **get_metrics_labels(scheduler_data)
+        ).observe(start_duration)
 
     _logger.info("Internal state after creating user services %s", scheduler_data)