Fix github-token attribute in preview workflow

[ricardozanini]

Quick fix for the GH attribute.

Warning: Unexpected input(s) 'github_token', valid inputs are ['name', 'path', 'pattern', 'merge-multiple', 'github-token', 'repository', 'run-id']
Run actions/download-artifact@v4
Downloading single artifact
Error: Unable to download artifact(s): Artifact not found for name: site
        Please ensure that your artifact is not expired and the artifact was uploaded using a compatible version of toolkit/upload-artifact.
        For more information, visit the GitHub Artifacts FAQ: https://github.com/actions/toolkit/blob/main/packages/artifact/docs/faq.md