Fix example CI to use secrets instead of env

Author: guylev008

.github/workflows/main.yml

@@ -62,5 +62,5 @@ jobs:
       - name: Install and run Spectral Audit
         uses: spectralops/spectral-github-action@v4
         with:
-          spectral-dsn: ${{ env.SPECTRAL_DSN }}
+          spectral-dsn: ${{ secrets.SPECTRAL_DSN }}
           spectral-args: github -k repo -t ${{ secrets.MY_GITHUB_TOKEN }} https://github.com/SpectralOps/spectral-github-action --include-tags base,audit --ok