fix: handle multiple repos in search query

[zkoppert]

Pull Request

fixes #256

Proposed Changes

This pull request includes changes to the issue_metrics.py and test_issue_metrics.py files. The changes are primarily aimed at allowing the search_issues function to search for issues in multiple GitHub repositories at once. This is achieved by modifying the function to accept a list of owners and repositories, instead of a single owner and repository.

Readiness Checklist

Author/Contributor

• If documentation is needed for this change, has that been included in this pull request
• run make lint and fix any issues that you have introduced
• run make test and ensure you have test coverage for the lines you are introducing

Reviewer

• Label as either fix, documentation, enhancement, infrastructure, maintenance, or breaking

[jmeridth]

🎉