Use actions/checkout@v4

Author: lauzadis

.github/actions/changelog-verification/action.yml

@@ -5,7 +5,7 @@ runs:
   using: "composite"
   steps:
     - name: Checkout sources
-      uses: actions/checkout@v2
+      uses: actions/checkout@v4
 
     - name: Setup kat
       uses: awslabs/aws-kotlin-repo-tools/.github/actions/setup-kat@main