chore(deps): update actions/checkout action to v4 (#500)

Author: renovate-bot

.github/workflows/test_suite.yml

@@ -137,7 +137,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
       - name: Setup Python
         uses: actions/setup-python@v4
         with: