ci: remove temporary npm auth token configuration step (#110)

The npm token is now handled via the setup-node action's registry-url,
making the explicit `npm config set` step redundant.

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: litianningdatadog

.github/workflows/publish.yml

@@ -123,9 +123,6 @@ jobs:
         with:
           node-version: "22.x"
           registry-url: 'https://registry.npmjs.org'
-      - run: npm config set //registry.npmjs.org/:_authToken=$NPM_PUBLISH_TOKEN
-        env:
-          NPM_PUBLISH_TOKEN: ${{ secrets.NPM_PUBLISH_TOKEN }}
       - name: Publish npm packages
         run: |
           npm publish ./npm/datadog-serverless-compat-linux-x64 --provenance --access public