[Pipeline](load) fix may oom in pipeline load (#27714)

be/src/pipeline/exec/olap_table_sink_operator.h

@@ -39,7 +39,7 @@ public:
     OlapTableSinkOperator(OperatorBuilderBase* operator_builder, DataSink* sink)
             : DataSinkOperator(operator_builder, sink) {}
 
-    bool can_write() override { return true; } // TODO: need use mem_limit
+    bool can_write() override { return _sink->can_write(); }
 };
 
 class OlapTableSinkOperatorX;