[Dy2St]Fix abnormal growth of memory in train mode and no_grad for Dy2St (#47398) (#47414)

* [Dy2St]Fix abnormal growth of memory in train mode and no_grad for Dy2St 

paddle/fluid/eager/to_static/run_program_op_node.h

@@ -394,7 +394,7 @@ inline void RunProgramAPI(
     }
     VLOG(3) << paddle::framework::GenScopeTreeDebugInfo(out_scope_vec->front());
 
-    if (is_test) {
+    if (is_test || !egr::Controller::Instance().HasGrad()) {
       VLOG(4) << "is test, set this scope can reused";
       global_inner_scope->SetCanReuesd(true);
       details::GcScope(global_inner_scope);
@@ -470,7 +470,7 @@ inline void RunProgramAPI(
     // Debug info: scope info when run end
     VLOG(3) << paddle::framework::GenScopeTreeDebugInfo(out_scope_vec->front());
     // Step 5. Drop all children scopes while testing.
-    if (is_test) {
+    if (is_test || !egr::Controller::Instance().HasGrad()) {
       out_scope_vec->front()->DropKids();
     }
     VLOG(2) << "The number of sub scopes after forward: "