feat: Ruby language support for jsii-rosetta #3711

Describe the feature

Add Ruby as a supported target language for jsii-rosetta, so the TypeScript example snippets embedded in CDK documentation are transliterated to idiomatic Ruby (for Construct Hub and inline docs), alongside the existing Python / Java / C# / Go renderers.

Part of the coordinated Ruby language support effort:

• RFC (umbrella tracking): Ruby Language Support aws-cdk-rfcs#935
• Downstream runtime + jsii-pacmak Ruby target: feat(ruby): Ruby language bindings jsii#5178

Proposed solution

A new RubyVisitor (src/languages/ruby.ts) that walks the TypeScript AST and renders idiomatic Ruby, registered as the RUBY target — the same visitor contract the other languages implement. Covered by translation fixtures and unit tests.

Scope & safety

• Strictly additive — a new visitor plus a target-enum entry; no existing language's output changes.
• Self-contained — the visitor has no dependency on the Ruby-capable jsii compiler, so the rosetta test suite passes on its own.
• Follows the established convention for src/languages/* visitors, so it is reviewable against the Python/Java precedent.

References

• RFC: Ruby Language Support aws-cdk-rfcs#935
• Implementing PR: feat: Ruby language support for jsii-rosetta #3710
• jsii monorepo (runtime + pacmak Ruby target): feat(ruby): Ruby language bindings jsii#5178