ci: run action self-test

Author: gchahal1982

.github/workflows/test-action.yml

@@ -8,4 +8,4 @@ jobs:
       - uses: actions/setup-node@v4
         with: { node-version: 20 }
       - run: npm install --no-audit --no-fund
-      - run: npm run build
+      - run: npm test