CapabilityService: Added check for no-op workflow event in update_execution

shared/workspaces/src/workspaces/services.py

@@ -112,6 +112,11 @@ class CapabilityService(CapabilityServiceIF):
         TODO: Implement execution cancellation
         """
         capability_event = self.workflow_to_capability_event(event)
+
+        if not capability_event:
+            # WorkflowEvent does not need to update the execution
+            return
+
         execution = self.capability_info.lookup_execution(capability_event.execution_id)
         step_sequence = CapabilitySequence.from_str(execution.steps)
         current_step = step_sequence[execution.current_step]