fix

Author: reakaleek

.github/workflows/pr.yml

@@ -39,6 +39,8 @@ jobs:
       # we run our artifact directly please use the prebuild
       # elastic/docs-builder@main GitHub Action for all other repositories!
       - name: Build documentation
+        env:
+          PR_NUMBER: ${{ github.event.pull_request.number }}
         run: .artifacts/publish/docs-builder/release/docs-builder --strict --path-prefix "/${GITHUB_REPOSITORY}/pull/${PR_NUMBER}"
 
       - uses: actions/upload-artifact@v4