update publish workflow to use actions v4

Fixes npm warning about deprecated always-auth config by updating
setup-node from v3 to v4.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.github/workflows/publish.yml

@@ -12,8 +12,8 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v3
-      - uses: actions/setup-node@v3
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
         with:
           node-version: lts/*
           registry-url: 'https://registry.npmjs.org'