fix(aci): catch correct DoesNotExist error (#105678)

We are querying DataCondition, not DataConditionGroup

Author: mifu67

src/sentry/workflow_engine/endpoints/validators/base/data_condition_group.py

@@ -30,7 +30,7 @@ def update_or_create_condition(self, condition_data: dict[str, Any]) -> DataCond
         if condition_id:
             try:
                 condition = DataCondition.objects.get(id=condition_id)
-            except DataConditionGroup.DoesNotExist:
+            except DataCondition.DoesNotExist:
                 raise serializers.ValidationError(f"Condition with id {condition_id} not found.")
 
             condition = validator.update(condition, condition_data)