update rubygems

.github/workflows/ruby.yml

@@ -20,8 +20,8 @@ jobs:
         uses: ruby/setup-ruby@v1
         with:
           bundler-cache: true
-      - name: Update Bundler
-        run: gem update bundler
+      - name: Update rubygems
+        run: gem update --system
       - name: Run linters
         run: bundle exec rubocop --parallel
       - name: Ruby security checks

Dockerfile

@@ -35,6 +35,8 @@ RUN --mount=type=cache,target=/var/cache/apt \
     libvips \
     pkg-config
 
+gem update --system
+
 # Install application gems
 COPY Gemfile Gemfile.lock ./
 RUN bundle install && \