[vector index] fix async task slice info memory leak

src/share/vector_index/ob_plugin_vector_index_service.cpp

@@ -894,6 +894,7 @@ int ObPluginVectorIndexService::release_vector_index_tmp_info(const int64_t task
     ret = OB_ERR_UNEXPECTED;
     LOG_WARN("unexpected nullptr", K(ret), K(task_id), K(tmp_info));
   } else {
+    tmp_info->reset();
     tmp_info->~ObVectorIndexTmpInfo();
     allocator_.free(tmp_info);
     tmp_info = nullptr;

src/share/vector_index/ob_plugin_vector_index_service.h

@@ -320,6 +320,7 @@ struct ObVectorIndexTmpInfo final
 public:
   ObVectorIndexTmpInfo() : snapshot_version_(0), schema_version_(0), ret_code_(OB_NOT_INIT), ddl_slice_info_(), adapter_(nullptr) {}
   ~ObVectorIndexTmpInfo() {}
+  void reset() { ddl_slice_info_.reset(); }
   TO_STRING_KV(K_(ddl_slice_info), KP_(adapter), K_(snapshot_version), K_(schema_version), K_(ret_code));
 
 public: