[CI] "Node.js 16 actions are deprecated. Please update the following …

…actions to use Node.js 20: actions/checkout@v3"

.github/workflows/main.yml

@@ -199,7 +199,7 @@ jobs:
     runs-on: ubuntu-20.04
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Set up Ruby
         uses: ruby/setup-ruby@v1
         with: