Updated GitHub Actions workflow to improve version handling and release management:

- Support version extraction with or without 'v' prefix (e.g., "1.2.3" and "v1.2.3")
- Create/update GitHub Releases for all version changes (major, minor, and patch)
- Improved release retention logic with clearer deletion rules for patch/minor/major releases
- Updated checkout action from v3 to v5 with full git history (fetch-depth: 0)
- Enhanced version parsing with better error handling and validation
- Clarified documentation for tagging rules and release-notes generation