Specify NodeProviderCollection element type

This stops PHPStan from complaining:

Class Ramsey\Uuid\Provider\Node\NodeProviderCollection extends generic class
Ramsey\Collection\AbstractCollection but does not specify its types: T

src/Provider/Node/NodeProviderCollection.php

@@ -20,6 +20,8 @@ use Ramsey\Uuid\Type\Hexadecimal;
 
 /**
  * A collection of NodeProviderInterface objects
+ *
+ * @extends AbstractCollection<NodeProviderInterface>
  */
 class NodeProviderCollection extends AbstractCollection
 {