Bug fixes

• #5537 Fix built-in shadow_matte AOV to match the common library shader shadow_matte
• #5551 Portals not working with unconnected skydome light color
• #5554 AiNodeDestroy sometimes returns wrong value when destroying procedural nodes
• #5561 Destroying a procedural node doesn't always release the node name
• #5562 Skydome light outside portals should be blocked