minor #16448 [Validator] Added missing ";" into Traverse.rst (NicolasJourdan)

This PR was submitted for the 6.0 branch but it was merged into the 5.3 branch instead.

Discussion
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[Validator] Added missing ";" into Traverse.rst

Added missing ";"

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Commits
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a358418 Update Traverse.rst

Author: javiereguiluz

reference/constraints/Traverse.rst

@@ -25,7 +25,7 @@ that all have constraints on their properties.
         namespace App\Entity;
 
         use Doctrine\Common\Collections\ArrayCollection;
-        use Doctrine\Common\Collections\Collection
+        use Doctrine\Common\Collections\Collection;
         use Doctrine\ORM\Mapping as ORM;
         use Symfony\Component\Validator\Constraints as Assert;