Slack v2 API usage

[glenn-jocher]

🛠️ PR Summary

_{Made with ❤️ by Ultralytics Actions}

🌟 Summary

This PR updates the Slack notification integration and increments the project version to 2.0.12.

📊 Key Changes

• Slack Integration Update: Upgraded slackapi/slack-github-action from version v1.26.0 to v2.0.0 and modified configuration syntax.
• Version Number Update: Changed the version number of the project from 2.0.11 to 2.0.12.

🎯 Purpose & Impact

• Improved Notification Stability: By updating to the latest Slack GitHub action version, the notifications for workflow success and failure should be more reliable and take advantage of recent improvements.
• Version Bump: The version increment indicates a small set of changes or bug fixes, helping users and developers keep track of updates and maintain synchronization with the latest codebase.

[UltralyticsAssistant]

👋 Hello @glenn-jocher, thank you for your contribution to the ultralytics/thop repository! 🚀 This is an automated response to assist you in ensuring your PR is ready for review. An Ultralytics engineer will be along shortly to provide additional feedback. Meanwhile, please review the checklist below to streamline the integration process:

• ✅ Define a Purpose: Ensure your PR description clearly outlines the purpose of your changes and links to any relevant issues. Accurate and descriptive commit messages are appreciated!
• ✅ Synchronize with Source: Check that your branch is up-to-date with the main branch of the repository. You can update it by pressing the 'Update branch' button or using git pull and git merge main locally.
• ✅ Ensure CI Checks Pass: Verify that all the Continuous Integration (CI) checks are successful. Please address any failing checks to maintain quality.
• ✅ Update Documentation: Be sure to update any relevant documentation to reflect your changes.
• ✅ Add Tests: Include new or update existing tests to verify your changes, ensuring all tests pass.
• ✅ Sign the CLA: If this is your first PR with us, please sign the Contributor License Agreement (CLA) by commenting "I have read the CLA Document and I sign the CLA".
• ✅ Minimize Changes: Aim to keep your changes as concise as possible, focusing on the essential modifications required for your update. "It is not daily increase but daily decrease, hack away the unessential." — Bruce Lee

Please consult our Contributing Guide for additional assistance. If any questions arise, feel free to ask here.

Thank you for your valuable contribution, and welcome aboard! 🌟