Fix typos in type hints (#41238)

Author: axlon

src/Illuminate/Collections/Enumerable.php

@@ -1074,7 +1074,7 @@ public function pipe(callable $callback);
     /**
      * Pass the collection into a new class.
      *
-     * @param  string-class  $class
+     * @param  class-string  $class
      * @return mixed
      */
     public function pipeInto($class);

src/Illuminate/Collections/Traits/EnumeratesValues.php

@@ -715,7 +715,7 @@ public function pipe(callable $callback)
     /**
      * Pass the collection into a new class.
      *
-     * @param  string-class  $class
+     * @param  class-string  $class
      * @return mixed
      */
     public function pipeInto($class)