Update ThemeTable.php

Set the limit 1 on fetching themes by anr and label.

src/Model/Table/ThemeTable.php

@@ -38,6 +38,7 @@ public function findByAnrIdAndLabel(?int $anrId, string $labelKey, string $label
         return $queryBuilder
             ->andWhere('t.' . $labelKey . ' = :' . $labelKey)
             ->setParameter($labelKey, $labelValue)
+            ->setMaxResults(1)
             ->getQuery()
             ->getOneOrNullResult();
     }