Fix issue preventing cleanup of vendor dir when it is nested in the install path on Windows, fixes #9396

src/Composer/Downloader/ArchiveDownloader.php

@@ -51,7 +51,7 @@ abstract class ArchiveDownloader extends FileDownloader
         // clean up the target directory, unless it contains the vendor dir, as the vendor dir contains
         // the archive to be extracted. This is the case when installing with create-project in the current directory
         // but in that case we ensure the directory is empty already in ProjectInstaller so no need to empty it here.
-        if (false === strpos($this->filesystem->normalizePath($vendorDir), $this->filesystem->normalizePath($path).DIRECTORY_SEPARATOR)) {
+        if (false === strpos($this->filesystem->normalizePath($vendorDir), $this->filesystem->normalizePath($path.DIRECTORY_SEPARATOR))) {
             $this->filesystem->emptyDirectory($path);
         }