Update .github/workflows/reusable-trufflehog.yml

Co-authored-by: James C <87319125+jamesc-grafana@users.noreply.github.com>

Author: isaiah-grafana

.github/workflows/reusable-trufflehog.yml

@@ -81,6 +81,9 @@ jobs:
 
       - name: Scan for secrets
         id: scan
+        environment:
+          BASE_REF: ${{ github.event.pull_request.base.ref }}
+          SHA: ${{ github.sha }}
         run: |
           set +e
           echo "[]" > results.json