Add ruby/setup-ruby step

Author: vallode

.github/workflows/update-definitions.yml

@@ -12,6 +12,10 @@ jobs:
       - uses: actions/checkout@v4
         with:
           submodules: true
+
+      - uses: ruby/setup-ruby@v1
+        with:
+          bundler-cache: true
 
       - name: Generate definitions
         run: rake build