chore: Update bundler cache setting in CI workflow

Author: hahwul

.github/workflows/ci.yml

@@ -23,6 +23,6 @@ jobs:
       uses: ruby/setup-ruby@v1
       with:
         ruby-version: ${{ matrix.ruby-version }}
-        bundler-cache: true # runs 'bundle install' and caches installed gems automatically
+        bundler-cache: false # runs 'bundle install' and caches installed gems automatically
     - name: Run tests
       run: rspec