chore: refactor rigging pr decorator

[GangGreenTemperTatum]

AI-Generated Summary

• Refactored the rigging_pr_decorator.py script to streamline PR description generation.
• Replaced class-based structure with a more functional approach:
  • Removed the PRDiffData and PRDecorator classes.
  • Introduced a simplified generate_pr_description function.
• Implemented a new get_diff function to handle git diff retrieval.
• Modified main function to use typer for command line interfacing.
• Adjusted the GitHub Actions workflow:
  • Changed PR trigger types from edited and reopened to opened and synchronize.
  • Removed unnecessary steps for direct diff retrieval, utilizing the refactored script.
• Environment setup now specifies Python 3.10.
• Improved error logging and streamlined dependency installation for better CI performance.
• Overall improvements should lead to more efficient and maintainable code for PR description generation.

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This summary was generated with ❤️ by rigging