Remove deprecated step (#1194)

Author: reakaleek

.github/workflows/preview-build.yml

@@ -175,10 +175,6 @@ jobs:
         if: contains(fromJSON('["push", "workflow_dispatch"]'), github.event_name) && (github.ref == 'refs/heads/main' || github.ref == 'refs/heads/master') && steps.s3-upload.outcome == 'success'
         uses: elastic/docs-builder/actions/update-link-index@main
 
-      - name: Update Reference Index
-        if: contains(fromJSON('["push", "workflow_dispatch"]'), github.event_name) && (github.ref == 'refs/heads/main' || github.ref == 'refs/heads/master') && steps.s3-upload.outcome == 'success'
-        uses: elastic/docs-builder/actions/update-reference-index@main
-
       - name: Update deployment status
         uses: actions/github-script@v7
         if: always() && steps.deployment.outputs.result