fix memory leak in HogwildWorker (#19956)

fix memory leak in HogwildWorker,  whose ops are  explicitly deleted in destructor

paddle/fluid/framework/device_worker.h

@@ -151,7 +151,12 @@ class CPUWorkerBase : public DeviceWorker {
 class HogwildWorker : public CPUWorkerBase {
  public:
   HogwildWorker() {}
-  virtual ~HogwildWorker() {}
+  virtual ~HogwildWorker() {
+    for (OperatorBase* op : ops_) {
+      delete op;
+    }
+    std::vector<OperatorBase*>().swap(ops_);
+  }
   virtual void Initialize(const TrainerDesc& desc);
   virtual void TrainFiles();
   virtual void TrainFilesWithProfiler();