Revert "[6.x] Fix memory usage on downloading large files (#31163)" (#…

…31587)

This reverts commit f239c07.

src/Illuminate/Filesystem/FilesystemAdapter.php

@@ -163,11 +163,7 @@ public function response($path, $name = null, array $headers = [], $disposition
 
         $response->setCallback(function () use ($path) {
             $stream = $this->readStream($path);
-
-            while (! feof($stream)) {
-                echo fread($stream, 2048);
-            }
-
+            fpassthru($stream);
             fclose($stream);
         });