Add a dependabot group for bundler updates matching 'rubocop*'

[markhallen]

Is your feature request related to a problem? Please describe.
Managing individual bundler dependency updates for gems matching the pattern "rubocop*" results in numerous separate PRs, making it harder to review and merge related updates efficiently.

Describe the solution you'd like
Introduce a dependabot group in the configuration that specifically bundles updates for dependencies matching the pattern "rubocop*". This will ensure that all rubocop-related updates are grouped into a single PR, simplifying dependency management and code review.

Describe alternatives you've considered

• Continue to review each rubocop-related dependency update individually.
• Use a broader grouping pattern, but prefer a focused approach for rubocop gems.

Additional context
This change will help reduce review overhead and keep the codebase up-to-date with rubocop and its extensions more efficiently.

Implementation ideas

• Update the dependabot configuration file (e.g., .github/dependabot.yml) to add a group with the pattern rubocop* for bundler updates.
• Example configuration:

  groups:
    rubocop:
      patterns:
        - "rubocop*"
      dependency_type: "direct"