Update actions/checkout action to v4

Author: renovate[bot]

.github/workflows/main.yml

@@ -20,7 +20,7 @@ jobs:
     # Steps represent a sequence of tasks that will be executed as part of the job
     steps:
     # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
 
     # Runs a single command using the runners shell
     - name: Run a one-line script