Update devdocs-notify.yml

Fix SLACK_WEBHOOK_URL variable

Author: antoniomorello-DB

.github/workflows/devdocs-notify.yml

@@ -14,7 +14,7 @@ jobs:
           PR_USER: ${{ github.event.pull_request.user.login }}
           PR_URL: ${{ github.event.pull_request.html_url }}
           REPO_NAME: ${{ github.repository }}
-          SLACK_WEBHOOK: ${{ secrets.SLACK_WEBHOOK }}
+          SLACK_WEBHOOK: ${{ secrets.SLACK_WEBHOOK_URL }}
         run: |
           # Build the message and payload in one step
           SLACK_PAYLOAD=$(jq -n \