build: actually run main() in index.ts (#882)

When converting to typescript we didn't call the main() method if
index.ts/js is invoked directly.

.github/workflows/release-please.yaml

@@ -62,7 +62,7 @@ jobs:
     runs-on: ubuntu-latest
     needs: [build]
     steps:
-      - uses: GoogleCloudPlatform/release-please-action@main
+      - uses: google-github-actions/release-please-action@main
         id: release
         with:
           token: ${{ secrets.GITHUB_TOKEN }}
@@ -90,7 +90,7 @@ jobs:
       - release-please-release
     steps:
       - id: release-pr
-        uses: GoogleCloudPlatform/release-please-action@main
+        uses: google-github-actions/release-please-action@main
         with:
           token: ${{ secrets.ACTIONS_BOT_TOKEN }}
           release-type: node