Update CI to use newer checkout and Node actions

Author: marcusschiesser

.github/workflows/ci.yml

@@ -11,19 +11,21 @@ jobs:
       contents: read
     steps:
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           persist-credentials: false
 
+      - name: Setup pnpm
+        uses: pnpm/action-setup@v4
+        with:
+          version: 11.4.0
+
       - name: Setup Node.js
-        uses: actions/setup-node@v4
+        uses: actions/setup-node@v6
         with:
           node-version: 24
           cache: pnpm
 
-      - name: Enable Corepack
-        run: corepack enable
-
       - name: Install dependencies
         run: pnpm install --frozen-lockfile