Firebase Hosting GitHub Action fails with "supplied version is the current active version" but changes are still deployed

This isn't a real failure — it's a no-op deploy. Firebase Hosting version IDs are hashes of your file set, so when a build produces identical content, the CLI reuses the existing version and tries to re-release the one that's already live, which 400s and exits 1.

Fix: only fail the step when it's not this specific case.

- name: Deploy Firebase
        run: |
          set +e
          OUT=$(npx firebase-tools@latest deploy \
            --project  \
            --only hosting 2>&1)
          CODE=$?
          echo "$OUT"
          if [ $CODE -ne 0 ] && echo "$OUT" | grep -q "is the current active version"; then
            echo "No content change — already live. Skipping."
            exit 0
          fi
          exit $CODE