chore(deps): update actions/setup-node action to v4 (googleapis#1943)

* chore(deps): update actions/setup-node action to v4

* 🦉 Updates from OwlBot post-processor

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

---------

Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>
Co-authored-by: surbhigarg92 <surbhigarg.92@gmail.com>
Co-authored-by: gcf-merge-on-green[bot] <60162190+gcf-merge-on-green[bot]@users.noreply.github.com>

.github/workflows/system-tests-against-emulator.yaml

@@ -17,7 +17,7 @@ jobs:
 
     steps:
       - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4
-      - uses: actions/setup-node@v3
+      - uses: actions/setup-node@v4
         with:
           node-version: 14
       - run: node --version