Bump actions/setup-node from 3 to 6 (#145)

Bumps [actions/setup-node](https://github.com/actions/setup-node) from 3 to 6.
- [Release notes](https://github.com/actions/setup-node/releases)
- [Commits](actions/setup-node@v3...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>

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -34,7 +34,7 @@ jobs:
         uses: actions/checkout@v4
 
       - name: Setup Node
-        uses: actions/setup-node@v4
+        uses: actions/setup-node@v6
         with:
           node-version: "20"
           cache: 'npm'

.github/workflows/deploy-to-pages.yml

@@ -38,7 +38,7 @@ jobs:
         uses: actions/checkout@v4
 
       - name: Setup Node
-        uses: actions/setup-node@v4
+        uses: actions/setup-node@v6
         with:
           node-version: "20"
           cache: 'npm'

.github/workflows/publish.yml

@@ -21,7 +21,7 @@ jobs:
         uses: actions/checkout@v3
 
       - name: Set up Node.js
-        uses: actions/setup-node@v3
+        uses: actions/setup-node@v6
         with:
           node-version: '22.x'
           registry-url: 'https://registry.npmjs.org'