Update deploy.yml (alshedivat#436)

‘action’ is deprecated, change to ‘ruby’
https://github.com/ruby/setup-ruby

Author: jmrplens

.github/workflows/deploy.yml

@@ -17,7 +17,7 @@ jobs:
     - name: Checkout code
       uses: actions/checkout@v2
     - name: Setup Ruby
-      uses: actions/setup-ruby@v1
+      uses: ruby/setup-ruby@v1
       with:
         ruby-version: '3.0.2'
     - name: Enable bundler cache