QTest::qWaitFor(., int): restore lost Qt::PreciseTimer'ness

Before the qWaitFor() port from int to QDeadlineTimer, the
implementation constructed a QDeadlineTimer internally, passing int
timeout and Qt::PreciseTimer. The int overload that was retained for
source-compatibility, however, constructs the QDeadlineTimer without
the PreciseTimer flag, which is a behavior change.

Restore the Qt 6.6 behavior and pass Qt::PreciseTimer.

Amends fa296ee1dc.

Pick-to: 6.7 6.7.0
Change-Id: Ib8e5b912c74b70d32a77195edb0d2a30cd7c241d
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>

src/corelib/kernel/qtestsupport_core.h

@@ -62,7 +62,7 @@ qWaitFor(Functor predicate, QDeadlineTimer deadline = QDeadlineTimer(std::chrono
 template <typename Functor>
 [[nodiscard]] static bool qWaitFor(Functor predicate, int timeout)
 {
-    return qWaitFor(predicate, QDeadlineTimer(timeout));
+    return qWaitFor(predicate, QDeadlineTimer{timeout, Qt::PreciseTimer});
 }
 
 Q_CORE_EXPORT void qWait(int ms);