Update sitemaps.yml

[glenn-jocher]

copilot:all

🛠️ PR Summary

_{Made with ❤️ by Ultralytics Actions}

🌟 Summary

Improvements to Sitemap Submission Workflow in Ultralytics Docs Repo 🚀

📊 Key Changes

• Added a new step to fetch the current and previous commit upon checking out the repository.
• Implemented a step to extract the list of modified files between the last two commits.
• Updated the sitemap submission script to include a new function that filters URLs by modified files.
• Now only the URLs corresponding to recently modified files are submitted to IndexNow, rather than all URLs.

🎯 Purpose & Impact

• 🎯 Purpose:
  • To optimize the process of updating search engines with changes to the documentation site.
  • To reduce resources and time by only processing modified files.
• 💥 Impact:
  • Users searching for Ultralytics documentation will find the most up-to-date contents more rapidly.
  • Improves SEO efficiency by focusing on newly updated pages, enhancing user experience with the freshest information.