test(ruby): regenerate target-ruby snapshot

The committed snapshot predated the autoload + RBS refactor, so it no longer
matched the generated code (Unit Tests failed). Regenerate it: this captures
the current per-type autoload layout, the sig/*.rbs signatures, and the new
per-submodule _readme.rb module-docstring files.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: omarqureshi