bundler support for ruby <= 3.0

Author: stefannibrasil

.github/workflows/ruby.yml

@@ -51,6 +51,7 @@ jobs:
     - uses: ruby/setup-ruby@v1
       with:
         ruby-version: ${{ matrix.ruby }}
+        bundler: ${{ (matrix.ruby <= '3.0' && '2.4.22') || 'latest' }}
 
     - name: Install dependencies
       run: bundle install