Don't throw exceptions on back-to-back window deactivations (#23519)

* Don't throw exceptions on back-to-back window deactivations, as this is valid behavior on platforms such as Windows.

* Switch activation logic check to be in MauiWinUIWindow

* Clarify comment

---------

Co-authored-by: Mike Corsaro <mikecorsaro@microsoft.com>

src/Core/src/Platform/Windows/MauiWinUIWindow.cs

@@ -75,6 +75,14 @@ protected virtual void OnActivated(object sender, UI.Xaml.WindowActivatedEventAr
 				else
 					_enableResumeEvent = true;
 			}
+			else if (args.WindowActivationState == UI.Xaml.WindowActivationState.Deactivated &&
+				!_isActivated)
+			{
+				// Don't invoke deactivated event if we're not activated. It's possible we can
+				// recieve this event multiple times if we start a new child process and that 
+				// process creates a new window
+				return;
+			}
 			else
 			{
 				_isActivated = false;