Specify BuilderCollection element type

This stops PHPStan from complaining:

Class Ramsey\Uuid\Builder\BuilderCollection extends generic class
Ramsey\Collection\AbstractCollection but does not specify its types: T

src/Builder/BuilderCollection.php

@@ -26,6 +26,8 @@ use Traversable;
 
 /**
  * A collection of UuidBuilderInterface objects
+ *
+ * @extends AbstractCollection<UuidBuilderInterface>
  */
 class BuilderCollection extends AbstractCollection
 {