Update CLA Action

[glenn-jocher]

🛠️ PR Summary

_{Made with ❤️ by Ultralytics Actions}

🌟 Summary

This PR updates the Contributor License Agreement (CLA) workflow for the YOLO repository.

📊 Key Changes

• Renamed references from "yolov5" to "YOLO" in documentation.
• Added permissions for actions, contents, pull-requests, and statuses.
• Updated the branch for storing CLA signatures from "main" to "cla-signatures".
• Clarified environment variable descriptions and included comments for better clarity.

🎯 Purpose & Impact

• Simplified Naming: Uses "YOLO" instead of "yolov5" to be consistent with the broader project naming.
• Improved Permissions: Ensures the workflow has the necessary permissions to function correctly.
• Better Organization: Changes the branch for CLA signatures to improve workflow management and organization.
• Clarity & Maintenance: Enhances documentation and comments for easier understanding and future maintenance.

These improvements streamline contributions, making the CLA process clearer and more efficient for contributors. 🚀