Avoid running script when failing on forks

Author: mfalt

.github/workflows/PingControlExamplePlots.yml

@@ -10,7 +10,11 @@ jobs:
     steps:
       - name: PR ping ControlExamplePlots
         run: |
+         if [ "$SECRET" != "" ]; then
           curl -X POST https://api.github.com/repos/JuliaControl/ControlExamplePlots.jl/dispatches \
           -H 'Accept: application/vnd.github.everest-preview+json' \
           -u ${{ secrets.ACCESS_TOKEN_BOT }} \
           --data '{"event_type": "prupdate", "client_payload": { "repository": "'"$GITHUB_REPOSITORY"'", "pr_number":  ${{ github.event.number }} }}'
+         fi
+        env:
+          SECRET: ${{ secrets.ACCESS_TOKEN_BOT }}