CI: Set ruby-version to ruby

This will default to the Ruby version from the action.
The option is required when there's no .ruby-version file.

Signed-off-by: Tim Meusel <tim@bastelfreak.de>

Author: bastelfreak

.github/workflows/components_update.yml

@@ -28,6 +28,7 @@ jobs:
       - name: Setup Ruby
         uses: ruby/setup-ruby@v1
         with:
+          ruby-version: 'ruby'
           bundler-cache: true
       - name: Add SSH key
         run: |