Added environment to the merge job. (#5764)

Co-authored-by: fulmicoton <paul.masurel@datadoghq.com>

Author: fulmicoton

.github/workflows/publish_docker_images.yml

@@ -93,6 +93,7 @@ jobs:
   merge:
     runs-on: ubuntu-latest
     needs: [docker]
+    environment: production
     steps:
       - name: Download digests
         uses: actions/download-artifact@v4.2.1