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

Author: renovate-bot

.github/workflows/ci.yml

@@ -51,7 +51,7 @@ jobs:
       with:
         ruby-version: "${{ matrix.ruby }}"
     - name: Install NodeJS 20.x
-      uses: actions/setup-node@v4
+      uses: actions/setup-node@v6
       with:
         node-version: "20.x"
     - name: Install tools and deps