GH Actions: Bump actions/setup-node from 3 to 4

Bumps [actions/setup-node](https://github.com/actions/setup-node) from 3 to 4.
- [Release notes](https://github.com/actions/setup-node/releases)
- [Commits](actions/setup-node@v3...v4)

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

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/markdown.yml

@@ -31,7 +31,7 @@ jobs:
       # This action also handles the caching of the dependencies.
       # https://github.com/actions/setup-node
       - name: Set up node and enable caching of dependencies
-        uses: actions/setup-node@v3
+        uses: actions/setup-node@v4
         with:
           node-version: '16'
 
@@ -59,7 +59,7 @@ jobs:
         uses: actions/checkout@v3
 
       - name: Set up node and enable caching of dependencies
-        uses: actions/setup-node@v3
+        uses: actions/setup-node@v4
         with:
           node-version: '16'