Fix Media Element fails to load a URL (#2265)

Enhance Dispose method for better resource management

Updated the Dispose method in MauiMediaElement.windows.cs to include:
- Pausing the media player before disposal.
- Explicitly disposing of MediaSource if used.
- Setting the media player's source to null.
- Disposing of the media player.
- Setting the media player element's media player to null.

These changes ensure proper release of resources, preventing memory leaks.

Co-authored-by: Brandon Minnick <[email protected]>
Co-authored-by: Brandon Minnick <[email protected]>

Author: ne0rrmatrix

src/CommunityToolkit.Maui.MediaElement/Views/MauiMediaElement.windows.cs

@@ -139,7 +139,17 @@ protected virtual void Dispose(bool disposing)
 
 		if (disposing)
 		{
+			mediaPlayerElement.MediaPlayer.Pause();
+			
+			if(mediaPlayerElement.MediaPlayer.Source is Windows.Media.Core.MediaSource mediaSource)
+			{
+				// Dispose the MediaSource to release the resources
+				// https://learn.microsoft.com/en-us/windows/uwp/audio-video-camera/play-audio-and-video-with-mediaplayer Shows how to dispose the MediaSource
+				mediaSource.Dispose();
+			}
+			mediaPlayerElement.MediaPlayer.Source = null;
 			mediaPlayerElement.MediaPlayer.Dispose();
+			mediaPlayerElement.SetMediaPlayer(null);
 		}
 
 		isDisposed = true;