chore(deps): bump actions/setup-node from 4 to 6 (#61)

Author: dependabot[bot]

.github/workflows/agent-validation.yml

@@ -46,7 +46,7 @@ jobs:
       - uses: actions/checkout@v6
         with:
           submodules: recursive
-      - uses: actions/setup-node@v4
+      - uses: actions/setup-node@v6
         with:
           node-version: 20
       - name: Validate module structure