fix npu client release problem

mindspore/lite/src/runtime/agent/npu/npu_executor.cc

@@ -20,6 +20,7 @@
 #include "nnacl/pack.h"
 namespace mindspore::lite {
 NPUExecutor::~NPUExecutor() {
+  client_.reset();
   npu_input_tensors_.clear();
   npu_output_tensors_.clear();
 }

mindspore/lite/src/runtime/agent/npu/npu_manager.cc

@@ -67,6 +67,7 @@ void NPUManager::Reset() {
       model->is_freed_ = true;
       model->desc_.reset();
       model->desc_ = nullptr;
+      model->client_.reset();
     }
   }
   models_.clear();