macOS: process all activation events synchronously

Commit ed483346 changed the main code path to deliver
activation events synchronously, however it looks like
an additional code path was missed.

Use SynchronousDelivery also in becomeFirstResponder.

Pick-to: 6.2
Change-Id: I9061868b0dd0db0252f281e3a974cffe795af38f
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>

src/plugins/platforms/cocoa/qnsview.mm

@@ -328,7 +328,8 @@ QT_NAMESPACE_ALIAS_OBJC_CLASS(QNSViewMouseMoveHelper);
         // QWindow activation from QCocoaWindow::windowDidBecomeKey instead. The only
         // exception is if the window can never become key, in which case we naturally
         // cannot wait for that to happen.
-        QWindowSystemInterface::handleWindowActivated([self topLevelWindow], Qt::ActiveWindowFocusReason);
+        QWindowSystemInterface::handleWindowActivated<QWindowSystemInterface::SynchronousDelivery>(
+            [self topLevelWindow], Qt::ActiveWindowFocusReason);
     }
 
     return YES;