ci: opt in to upstream bundle-build smoke check (#291)

Sets `bundle-build: true` on the reusable `service-ci.yaml@v2` workflow.
This adds a Lambda bundle smoke check (`npm run build` =
helix-deploy `--test-bundle`) to the build job — bundles the Lambda
artifact and invokes the bundled `lambda()` against a synthetic
healthcheck event, exiting non-zero on any non-2xx response.

Catches module-load failures that source-based unit tests miss
(missing static assets, `readFileSync(import.meta.url)` bundle drops,
top-level FS/network access at module load), e.g. SITES-45260.

See adobe/mysticat-ci#17.

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: rainer-friederich

.github/workflows/ci.yaml

@@ -17,4 +17,5 @@ jobs:
     with:
       service-name: task-processor
       vpc-enabled: true
+      bundle-build: true
     secrets: inherit