Improve Release Summary action

[glenn-jocher]

🛠️ PR Summary

_{Made with ❤️ by Ultralytics Actions}

🌟 Summary

Enhancements to the issue autolabeling, PR summarization, and release note generation scripts.

📊 Key Changes

• Refactored HTML Comment Removal: Extracted the function to remove HTML comments into a reusable function.
• Adjusted Completion Functions: Simplified completion function calls by removing unused parameters.
• Enhanced Release Summary Generation:
  • Added retrieval of merged PRs between tags.
  • Prioritized PR summaries in release notes for better clarity.
  • Implemented a function to get the previous tag for generating diffs.
• Cleaned Up Environment Variables: Removed unnecessary environment variables for a cleaner setup.

🎯 Purpose & Impact

• Improved Code Reusability: By refactoring the comment removal function, the code is now cleaner and more maintainable.
• Simplified API Calls: The changes to the completion functions and release summary generation make the scripts more straightforward and efficient.
• Better Release Notes: Including detailed PR summaries makes release notes more informative and helpful for users.
• Streamlined Setup: Removing unneeded environment variables reduces potential setup issues and simplifies the development process.