Update lock return type (#39859)

Author: maxsky

src/Illuminate/Cache/Lock.php

@@ -98,7 +98,7 @@ public function get($callback = null)
      *
      * @param  int  $seconds
      * @param  callable|null  $callback
-     * @return bool
+     * @return mixed
      *
      * @throws \Illuminate\Contracts\Cache\LockTimeoutException
      */

src/Illuminate/Contracts/Cache/Lock.php

@@ -17,7 +17,7 @@ public function get($callback = null);
      *
      * @param  int  $seconds
      * @param  callable|null  $callback
-     * @return bool
+     * @return mixed
      */
     public function block($seconds, $callback = null);