ci: cleanup workaround for broken bundler version

Author: flavorjones

.github/workflows/gem-install.yml

@@ -74,8 +74,7 @@ jobs:
         with:
           name: gem-x86_64-linux
           path: pkg
-      - run: "gem update --system"
-      - run: "apk add build-base" # TODO: remove after https://github.com/rubygems/rubygems/issues/5914 is in a rubygems release
+      - run: "gem update --system" # let's make sure the latest is working for us (upstream test, see #200)
       - run: "gem install pkg/tailwindcss-rails-*.gem"
       - run: "tailwindcss --help"