This helps investigate test failures

In this way, we can avoid the need to specify `BUNDLE_BUILD__JS=--enable-component-model`
when running `bundle install` for the `js` gem. When running `bundle install`, it's usually
dynamic-linking enabled, so it makes sense to enable the component model by default.

…nstall"

The ruby-head-wasm-wasi's Gemfile uses vendor/cache to install js gem
but the cache gem is not yet available at setup-time. And also with
cache gem, the Gemfile is not needed to be installed at setup-time.
So just skip the Gemfile installation here

beause it requires gems listed in the Gemfile to be installed

to integrate with Bundler in-process

Seems like extension build process is confused by the presence of
/usr/local/include/ruby/config.h