Add label checker workflow For Breaking/Non-Breaking Changes

[matthewkrausse]

What is this change?

• Introduces a GitHub Actions workflow to enforce label requirements on pull requests.
• Updates the pull request template to include instructions for adding required labels.

Considerations for discussion

• The workflow ensures that each pull request has either a breaking-change or non-breaking-change label, preventing both from being applied simultaneously.

How to test the changes (if needed)

• Add the two labels to our repo.
• Create a pull request and verify that the label check workflow runs, ensuring that it enforces the label requirements correctly.

[github-actions]

Coverage report

This PR does not seem to contain any modification to coverable code.