Removed brittle checks in connection_pool_cancel test

These checks could cause false positive race conditions to be reported.

test/thread_safety/connection_pool_cancel.cpp

@@ -9,12 +9,10 @@
 #include <boost/mysql/pool_params.hpp>
 
 #include <boost/asio/bind_executor.hpp>
-#include <boost/asio/cancel_after.hpp>
 #include <boost/asio/detached.hpp>
 #include <boost/asio/post.hpp>
 #include <boost/asio/thread_pool.hpp>
 
-#include <chrono>
 #include <memory>
 
 #include "tsan_pool_common.hpp"
@@ -31,7 +29,6 @@ void run(const char* hostname)
     // Setup
     asio::thread_pool ctx(8);
 
-    // Using cancel()
     for (int i = 0; i < 20; ++i)
     {
         // Create a pool
@@ -44,16 +41,6 @@ void run(const char* hostname)
         asio::post(asio::bind_executor(ctx.get_executor(), [pool]() { pool->cancel(); }));
     }
 
-    // Using per-operation cancellation
-    for (int i = 0; i < 20; ++i)
-    {
-        // Create a pool
-        mysql::connection_pool pool(ctx, create_pool_params(hostname, 10));
-
-        // Run the pool for a short period of time
-        pool.async_run(asio::cancel_after(std::chrono::milliseconds(1), asio::detached));
-    }
-
     // Run
     ctx.join();
 }