Adds error handler for Ruby version not found class error

[sachin-sandhu]

What are you trying to accomplish?

Adds error handler for Ruby version not found class so that they don't end up being in Sentry.

Dependabot::Bundler::FileUpdater::RubyRequirementSetter::RubyVersionNotFound: Dependabot::Bundler::FileUpdater::RubyRequirementSetter::RubyVersionNotFound
  bundler/lib/dependabot/bundler/file_updater/ruby_requirement_setter.rb:65:in `ruby_version'
  bundler/lib/dependabot/bundler/file_updater/ruby_requirement_setter.rb:33:in `rewrite'
  bundler/lib/dependabot/bundler/update_checker/file_preparer.rb:262:in `block in lock_ruby_version'
  bundler/lib/dependabot/bundler/update_checker/file_preparer.rb:260:in `each'
  bundler/lib/dependabot/bundler/update_checker/file_preparer.rb:260:in `lock_ruby_version'

...
(50 additional frame(s) were not displayed)

Anything you want to highlight for special attention from reviewers?

How will you know you've accomplished your goal?

Checklist

• I have run the complete test suite to ensure all tests and linters pass.
• I have thoroughly tested my code changes to ensure they work as expected, including adding additional tests for new functionality.
• I have written clear and descriptive commit messages.
• I have provided a detailed description of the changes in the pull request, including the problem it addresses, how it fixes the problem, and any relevant details about the implementation.
• I have ensured that the code is well-documented and easy to understand.