Bump setup-node to v6, re-enable cache (#36207)

.github/workflows/release-nightly.yml

@@ -23,9 +23,11 @@ jobs:
           go-version-file: go.mod
           check-latest: true
       - uses: pnpm/action-setup@v4
-      - uses: actions/setup-node@v5
+      - uses: actions/setup-node@v6
         with:
           node-version: 24
+          cache: pnpm
+          cache-dependency-path: pnpm-lock.yaml
       - run: make deps-frontend deps-backend
       # xgo build
       - run: make release