www/rubygem-stimulus-rails-rails71: Add rubygem-stimulus-rails-rails71 1.3.4

Stimulus is a JavaScript framework with modest ambitions. It doesn't seek to
take over your entire front-end in fact, it's not concerned with rendering HTML
at all. Instead, it's designed to augment your HTML with just enough behavior to
make it shine. Stimulus pairs beautifully with Turbo to provide a complete
solution for fast, compelling applications with a minimal amount of effort.
Together they form the core of Hotwire.

Stimulus for Rails makes it easy to use this modest framework with both
import-mapped and JavaScript-bundled apps. It relies on either importmap-rails
to make Stimulus available via ESM or a Node-capable Rails (like via
jsbundling-rails) to include Stimulus in the bundle. Make sure to install one of
these first!