Add some missing return types to internal/final classes

Author: nicolas-grekas

Authorization/Voter/TraceableVoter.php

@@ -33,7 +33,7 @@ public function __construct(VoterInterface $voter, EventDispatcherInterface $eve
         $this->eventDispatcher = $eventDispatcher;
     }
 
-    public function vote(TokenInterface $token, $subject, array $attributes)
+    public function vote(TokenInterface $token, $subject, array $attributes): int
     {
         $result = $this->voter->vote($token, $subject, $attributes);