Update main.yml

.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
       name: Checkout source branch
     - uses: gaurav-nelson/github-action-markdown-link-check@v1
       name: Check links