Refactoring & CI updates

[aliyuldashev]

This pull request introduces several improvements to the CI/CD pipeline configuration and enhances the scoring logic in the validator core. The main changes include updating GitHub Actions to use the latest checkout version, adding Docker support to Dependabot, and refining commit scoring by removing lower-than-highest scores and ensuring proper sorting when updating miner scores.

CI/CD Pipeline Improvements:

• Updated all GitHub Actions workflows to use actions/checkout@v6 instead of @v5 for improved security and features (.github/workflows/1.bump-version.yml, .github/workflows/2.build-publish.yml, .github/workflows/3.create-release.yml, .github/workflows/4.update-changelog.yml). [1] [2] [3] [4]
• Added Docker as a monitored ecosystem in Dependabot configuration to automatically check for Docker dependency updates (.github/dependabot.yml).

Validator Scoring Logic Enhancements:

• In src/validator/_core.py, after removing redundant logs, now also removes scores lower than the highest for each commit to ensure only the best score is retained (remove_lower_than_highest_score method). [1] [2]
• When updating miner scores, now sorts scored commits by timestamp to ensure the most recent scores are used (_sync_state_from_scored_commits).
• Minor import formatting improvement for clarity.