Upgrade the checkout action version.

Author: petergoldstein

.github/workflows/ruby.yml

@@ -31,7 +31,7 @@ jobs:
         ruby-version: ['2.7', '3.0', '3.1', '3.2']
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
     - name: Set up Ruby
       uses: ruby/setup-ruby@v1
       with: