Try not bundling explicitly

Author: brendon

.github/workflows/test.yml

@@ -80,11 +80,6 @@ jobs:
         uses: ruby/setup-ruby@v1
         with:
           ruby-version: ${{ matrix.ruby }}
-      - name: Bundle
-        run: |
-          gem update --system
-          gem install bundler
-          bundle install --jobs 4 --retry 3
         env:
           BUNDLE_GEMFILE: gemfiles/rails_${{ matrix.rails }}.rb