Update format.yml for PR types

[glenn-jocher]

🛠️ PR Summary

_{Made with ❤️ by Ultralytics Actions}

🌟 Summary

Improved automation for pull request formatting checks. 🤖✅

📊 Key Changes

• Modified the trigger events for formatting workflows in pull requests.
• Previously, the workflow was triggered for PRs to main and develop branches.
• Now, it is triggered on PR opening, closing, and synchronization (new commits).

🎯 Purpose & Impact

• Ensures consistent code formatting across different stages of the PR lifecycle. 🛠️
• Provides immediate feedback for contributors when PRs are opened, updated, or closed. 🔄
• Increases workflow efficiency and helps maintain code quality for users and developers. 👨‍💻👩‍💻