[EventEngine] Remove invalid IOCP closed socket test (#37864)

The [CreateIoCompletionPort ](https://learn.microsoft.com/en-us/windows/win32/fileio/createiocompletionport) API specifies that the handle must either be open, or explicitly the `INVALID_HANDLE_VALUE` value. Testing the API with a closed socket is apparently UB.

Closes #37864

COPYBARA_INTEGRATE_REVIEW=https://github.com/grpc/grpc/pull/37864 from drfloob:rm-iocp-ub-test 514e899899
PiperOrigin-RevId: 683647143

test/core/event_engine/windows/iocp_test.cc

@@ -250,16 +250,6 @@ TEST_F(IOCPTest, KickThenShutdownCasusesNextWorkerToBeKicked) {
   thread_pool->Quiesce();
 }
 
-TEST_F(IOCPTest, CrashOnWatchingAClosedSocket) {
-  auto thread_pool = grpc_event_engine::experimental::MakeThreadPool(8);
-  IOCP iocp(thread_pool.get());
-  SOCKET sockpair[2];
-  CreateSockpair(sockpair, iocp.GetDefaultSocketFlags());
-  closesocket(sockpair[0]);
-  ASSERT_DEATH({ auto wrapped_client_socket = iocp.Watch(sockpair[0]); }, "");
-  thread_pool->Quiesce();
-}
-
 TEST_F(IOCPTest, StressTestThousandsOfSockets) {
   // Start 10 threads, each with their own IOCP
   // On each thread, create 50 socket pairs (100 sockets) and have them exchange