TaskTree: Preserve the right order of the 0 TimeoutTask

Like it's done for all other TimeoutTasks.
Before it was flaky on mac.

Change-Id: I2999b1264d313dda5d614d9dbd7ae03b2bf00fb0
Reviewed-by: Marcus Tillmanns <marcus.tillmanns@qt.io>

src/libs/solutions/tasking/tasktree.cpp

@@ -2728,9 +2728,6 @@ TimeoutTaskAdapter::~TimeoutTaskAdapter()
 
 void TimeoutTaskAdapter::start()
 {
-    if (*task() == milliseconds::zero())
-        QTimer::singleShot(0, this, [this] { emit done(true); });
-    else
     m_timerId = scheduleTimeout(*task(), this, [this] { m_timerId = {}; emit done(true); });
 }