DYN-5656 Preferences Blocking Action Bug (#14837)

If we open the PackageManager from Preferences panel and then back to Preferences panel using the link then after closing preferences the background was still present.
So with this fix is removing the background under the described specfic case.

src/DynamoCoreWpf/Views/PackageManager/PackageManagerView.xaml.cs

@@ -130,8 +130,7 @@ private void PackageManagerPanel_MouseDown(object sender, MouseButtonEventArgs e
         /// <param name="e"></param>
         private void CloseButton_Click(object sender, RoutedEventArgs e)
         {
-            Analytics.TrackEvent(Actions.Close, Categories.PackageManager);
-            (this.Owner as DynamoView).EnableOverlayBlocker(false);
+            Analytics.TrackEvent(Actions.Close, Categories.PackageManager);           
 
             Close();
         }
@@ -143,6 +142,7 @@ private void WindowClosed(object sender, EventArgs e)
         {
             this.packageManagerPublish?.Dispose();
             this.packageManagerSearch?.Dispose();
+            (this.Owner as DynamoView).EnableOverlayBlocker(false);
 
             if (PackageManagerViewModel == null) return;
             this.PackageManagerViewModel.PackageSearchViewModel.RequestShowFileDialog -= OnRequestShowFileDialog;