Update PR Difficulty Rating action to always use the latest version.

[github-actions[bot]]

• Rule: Diff only contains changes to the PR rating workflow, no significant code change. It's a simple update to an existing GitHub action, which doesn't involve any complex refactoring or new features.

• Reason: The changes in this PR are limited to updating the version of a GitHub action used in the PR rating process. This is unlikely to introduce bugs or require extensive review.
• Impact on codebase: Low, as it only affects the internal workflow for rating pull requests.
• Recommended reviewers: Any developer familiar with GitHub actions and the existing rating system can review this PR.

[github-actions[bot]]

The PR is categorized as 'BLACK' due to the following reasons:

• The .github/workflows/pr-rating.yml file has been modified, which contains the workflow for rating the difficulty of pull requests in this repository.
• There is a change in the version of the rate-my-pr/rate action used in the workflow. Specifically, it was updated from v1.0.11 to v1. This could potentially introduce new features or changes that affect the rating process, which requires deep understanding of the project architecture.