ci: update actions/setup-node action to v6

Author: renovate[bot]

.github/workflows/chromatic.yml

@@ -10,7 +10,7 @@ jobs:
         with:
           fetch-depth: 0
 
-      - uses: actions/setup-node@v4
+      - uses: actions/setup-node@v6
         with:
           node-version-file: .node-version