Add missing return type annotation in AuraSqlQueryPager

This change adds the missing return type annotation for the `init` method in `AuraSqlQueryPager`. It improves code readability and ensures better static analysis compatibility.

src/Pagerfanta/AuraSqlQueryPager.php

@@ -39,6 +39,9 @@ public function __construct(private readonly ViewInterface $view, private readon
 
     /**
      * @phpstan-param positive-int $paging
+     *
+     * @return AuraSqlQueryPagerInterface
+     *
      * {@inheritDoc}
      */
     public function init(ExtendedPdoInterface $pdo, SelectInterface $select, int $paging, RouteGeneratorInterface $routeGenerator)