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

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>

.github/workflows/benchmark.yml

@@ -62,7 +62,7 @@ jobs:
           go-version: "1.23.x"
 
       - name: Setup Node.js
-        uses: actions/setup-node@v4
+        uses: actions/setup-node@v6
         with:
           node-version: '20'
 

.github/workflows/sync-docs.yml

@@ -23,7 +23,7 @@ jobs:
                   fetch-depth: 2
 
             - name: Setup Node.js environment
-              uses: actions/setup-node@v4
+              uses: actions/setup-node@v6
               with:
                   node-version: '20'
 

.github/workflows/test-cloudflarekv.yml

@@ -29,7 +29,7 @@ jobs:
           go-version: ${{ matrix.go-version }}
 
       - name: Setup Node.js
-        uses: actions/setup-node@v4
+        uses: actions/setup-node@v6
         with:
           node-version: '20'