add missing return datatype (#31654)

Author: nguyenyou

src/Illuminate/Queue/Console/ListFailedCommand.php

@@ -92,7 +92,7 @@ private function extractJobName($payload)
      * Match the job name from the payload.
      *
      * @param  array  $payload
-     * @return string
+     * @return string|null
      */
     protected function matchJobName($payload)
     {

src/Illuminate/Queue/Jobs/RedisJob.php

@@ -110,7 +110,7 @@ public function attempts()
     /**
      * Get the job identifier.
      *
-     * @return string
+     * @return string|null
      */
     public function getJobId()
     {

src/Illuminate/Routing/Route.php

@@ -686,7 +686,7 @@ public function getDomain()
     /**
      * Get the prefix of the route instance.
      *
-     * @return string
+     * @return string|null
      */
     public function getPrefix()
     {
@@ -734,7 +734,7 @@ public function setUri($uri)
     /**
      * Get the name of the route instance.
      *
-     * @return string
+     * @return string|null
      */
     public function getName()
     {