Change `callback` to `callable`

src/Composer/Repository/Vcs/GitHubDriver.php

@@ -33,7 +33,7 @@ class GitHubDriver extends VcsDriver
      * @param string $url
      * @param IOInterface $io
      * @param ProcessExecutor $process
-     * @param callback $remoteFilesystemGenerator
+     * @param callable $remoteFilesystemGenerator
      */
     public function __construct($url, IOInterface $io, ProcessExecutor $process = null, $remoteFilesystemGenerator = null)
     {

src/Composer/Repository/Vcs/VcsDriver.php

@@ -35,7 +35,7 @@ abstract class VcsDriver implements VcsDriverInterface
      * @param string      $url The URL
      * @param IOInterface $io  The IO instance
      * @param ProcessExecutor $process  Process instance, injectable for mocking
-     * @param callback $remoteFilesystemGenerator Generates Remote Filesystem, injectable for mocking
+     * @param callable $remoteFilesystemGenerator Generates Remote Filesystem, injectable for mocking
      */
     public function __construct($url, IOInterface $io, ProcessExecutor $process = null, $remoteFilesystemGenerator = null)
     {