Update node-version format in CI workflow

Change double quotes to single quotes for consistency in the node-version declaration. This adheres to the coding style guidelines and prevents potential issues with YAML parsers.

.github/workflows/ci.yml

@@ -20,10 +20,10 @@ jobs:
       - name: Use Node.js
         uses: actions/setup-node@v4
         with:
-          node-version: "20"
+          node-version: '20'
 
       - name: Install dependencies
         run: npm install
 
       - name: Run CI
-        run: npm run ci
+        run: npm run ci