feat: extend support modes in variable aggregation node to include knowledge workflows

Author: liuruibin

apps/application/flow/step_node/variable_aggregation_node/i_variable_aggregation_node.py

@@ -28,7 +28,7 @@ class VariableAggregationNodeSerializer(serializers.Serializer):
 
 class IVariableAggregation(INode):
     type = 'variable-aggregation-node'
-    support = [WorkflowMode.APPLICATION, WorkflowMode.APPLICATION_LOOP]
+    support = [WorkflowMode.APPLICATION, WorkflowMode.APPLICATION_LOOP, WorkflowMode.KNOWLEDGE, WorkflowMode.KNOWLEDGE_LOOP]
 
     def get_node_params_serializer_class(self) -> Type[serializers.Serializer]:
         return VariableAggregationNodeSerializer