rubocop.yml in image_optim-0.31.3

- old
+ new

@@ -6,11 +6,11 @@
   - cron: 45 4 * * 2
 jobs:
   rubocop:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
     - uses: ruby/setup-ruby@v1
       with:
-        ruby-version: '3.1'
+        ruby-version: '3'
         bundler-cache: true
     - run: bundle exec rubocop