test, bench: make prevector and checkqueue swap member functions noexcept

Reason:
A swap must not fail; when a class has a swap member function, it should be declared noexcept.
https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#c84-a-swap-function-must-not-fail

src/bench/checkqueue.cpp

@@ -39,7 +39,10 @@ static void CCheckQueueSpeedPrevectorJob(benchmark::Bench& bench)
         {
             return true;
         }
-        void swap(PrevectorJob& x){p.swap(x.p);};
+        void swap(PrevectorJob& x) noexcept
+        {
+            p.swap(x.p);
+        };
     };
     CCheckQueue<PrevectorJob> queue {QUEUE_BATCH_SIZE};
     // The main thread should be counted to prevent thread oversubscription, and