Ruby: Improve native extension loading for preview versions

[marcoroth]

This pull request improves how the herb gem loads its native extension, particularly for users running preview/development versions of Ruby.

1. Detect preview Ruby versions (RUBY_PATCHLEVEL == -1) and skip precompiled extensions to avoid ABI incompatibility errors like undefined symbol: ruby_abi_version

2. Add helpful error messages when the native extension fails to load, including:

   • What paths were tried
   • Common causes (preview Ruby, missing compilation, missing build tools)
   • How to reinstall with source compilation
   • Platform-specific instructions for installing C compilers

3. Remove unnecessary rake templates call from extconf.rb since generated files are already bundled in the gem

Resolves #880
Resolves #951
Resolves #1046

[pkg-pr-new]

npx https://pkg.pr.new/@herb-tools/formatter@1081

npx https://pkg.pr.new/@herb-tools/language-server@1081

npx https://pkg.pr.new/@herb-tools/linter@1081

commit: 6e125bb

[github-actions]

🌿 Interactive Playground and Documentation Preview

A preview deployment has been built for this pull request. Try out the changes live in the interactive playground:

• Playground Preview
• Documentation Preview
• Website Preview

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_{🌱 Grown from commit 6e125bb}

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✅ Preview deployment has been cleaned up.