fix(TopFloorPlugin): try other way to autoload

src/ParentPlugin.php

@@ -12,7 +12,7 @@ use Composer\IO\IOInterface;
 use Composer\Plugin\PluginInterface;
 use TopFloor\ComposerCleanupVcsDirs\Plugin as TopFloorPlugin;
 
-if (class_exists(TopFloorPlugin::class,false)){
+if (file_exists(__DIR__.'/../../../topfloor/composer-cleanup-vcs-dirs/src/Plugin.php') && class_exists(TopFloorPlugin::class,true)){
     abstract class ParentPlugin extends TopFloorPlugin
     {
         /**