chore(deps): update actions/setup-node action to v6

Signed-off-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/deploy.yml

@@ -24,7 +24,7 @@ jobs:
           extended: true
 
       - name: Use Node.js 18
-        uses: actions/setup-node@v4
+        uses: actions/setup-node@v6
         with:
           node-version: 18
 

.github/workflows/link-check.yml

@@ -23,7 +23,7 @@ jobs:
           extended: true
 
       - name: Use Node.js 18
-        uses: actions/setup-node@v4
+        uses: actions/setup-node@v6
         with:
           node-version: 18