Update actions/checkout action to v4 (#41)

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

Author: renovate[bot]

.github/workflows/test.yml

@@ -15,7 +15,7 @@ jobs:
     name: "Test build of example projects"
     steps:
       - name: Checkout
-        uses: actions/checkout@v3.5.3
+        uses: actions/checkout@v4.1.1
       - name: Setup Node.js
         uses: actions/setup-node@v3.7.0
       - name: Setup pnpm