fix: don't assume item id and library options are available

Don't assume the `ItemId` and `LibraryOptions` are always available on `VirtualFolderInfo`. They can both be null if the library failed to be parsed.

Shokofin/Configuration/MediaFolderConfigurationService.cs

@@ -301,7 +301,8 @@ public async Task<MediaFolderConfiguration> GetOrCreateConfigurationForMediaFold
     private async Task GenerateAllConfigurations(List<VirtualFolderInfo> allVirtualFolders)
     {
         var filteredVirtualFolders = allVirtualFolders
-            .Where(virtualFolder => 
+            .Where(virtualFolder =>
+                virtualFolder is { ItemId: not null, LibraryOptions: { } } &&
                 virtualFolder.CollectionType.ConvertToCollectionType() is null or CollectionType.movies or CollectionType.tvshows &&
                 Lookup.IsEnabledForLibraryOptions(virtualFolder.LibraryOptions, out _)
             )