fix push_gem.yml

Author: joelhawksley

.github/workflows/push_gem.yml

@@ -32,7 +32,7 @@ jobs:
         uses: ruby/setup-ruby@v1
         with:
           bundler-cache: true
-          ruby-version: ruby
+          ruby-version: 3.4
 
       # Release
       - uses: rubygems/release-gem@v1