[native] Fix unused variable error (#24117)

Summary:
Some builds were failing due to this unused variable which was imported as part of D65695576.
https://www.internalfb.com/sandcastle/workflow/3868592079916467326


Reviewed By: yuandagits

Differential Revision: D66350671

Pulled By: HeidiHan0000

presto-native-execution/presto_cpp/main/tests/TaskManagerTest.cpp

@@ -802,7 +802,6 @@ DEBUG_ONLY_TEST_P(TaskManagerTest, fecthFromArbitraryOutput) {
   const protocol::Duration longWait("10s");
   const auto maxSize = protocol::DataSize("1024MB");
   auto expiredRequestState = http::CallbackRequestHandlerState::create();
-  auto consumeCompleted = false;
   // Consume from destination 0 to simulate the case that the http request has
   // expired while destination has notify setup.
   auto expiredResultWait = taskManager_->getResults(