HADOOP-19193. Create orphan commit for website deployment (#6864)

This stop gh-pages deployments from increasing the size of the git repository on every run

Contributed by Cheng Pan

.github/workflows/website.yml

@@ -56,4 +56,5 @@ jobs:
           publish_dir: ./staging/hadoop-project
           user_name: 'github-actions[bot]'
           user_email: 'github-actions[bot]@users.noreply.github.com'
+          force_orphan: true