Update actions/checkout action to v7

Author: renovate[bot]

.github/workflows/auto.yml

@@ -13,7 +13,7 @@ jobs:
 
     steps:
     - name: Checking out Repository
-      uses: actions/checkout@v2
+      uses: actions/checkout@v7.0.0
       with:
         ref: gh-pages
     - name: Setting up node.js