chore: change to action

Author: vladfrangu

.github/workflows/pr-previews.yaml

@@ -27,6 +27,6 @@ jobs:
 
     steps:
       - name: Delete preview
-        run: gh workflow run apify_docs_pr.yml --repo apify/apify-docs-private --field pr-number=${{ github.event.pull_request.number }} --field original-repo=${{ github.repository }} --field delete-preview=true
+        run: gh workflow run apify_docs_pr.yml --repo apify/apify-docs-private --field pr-number=${{ github.event.pull_request.number }} --field original-repo=${{ github.repository }} --field action=delete
         env:
           GH_TOKEN: ${{ secrets.APIFY_SERVICE_ACCOUNT_GITHUB_TOKEN }}