build(deps): bump actions/setup-node from 4 to 6 (#61769)

Bumps [actions/setup-node](https://github.com/actions/setup-node) from 4 to 6.
- [Release notes](https://github.com/actions/setup-node/releases)
- [Commits](https://github.com/actions/setup-node/compare/v4...v6)

---
updated-dependencies:
- dependency-name: actions/setup-node
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/docs-sync-publish.yml

@@ -23,7 +23,7 @@ jobs:
           fetch-depth: 0
 
       - name: Setup Node
-        uses: actions/setup-node@v4
+        uses: actions/setup-node@v6
         with:
           node-version: "22.18.0"
 

.github/workflows/parity-gate.yml

@@ -54,7 +54,7 @@ jobs:
         uses: pnpm/action-setup@v4
 
       - name: Setup Node
-        uses: actions/setup-node@v4
+        uses: actions/setup-node@v6
         with:
           node-version: "22.18.0"
           cache: "pnpm"