Sitemaps ping is deprecated. See https://developers.google.com/search/blog/2023/06/sitemaps-lastmod-ping.

The message you're seeing refers to the fact that Google's Sitemaps ping service has been deprecated as of June 2023. This means that Google no longer supports the ability to "ping" or directly notify Google when you've updated your sitemap.

What should you do now? You don't need to worry too much about manually submitting your sitemap to Google anymore. Instead, follow these steps:

1. Ensure the sitemap is accessible: Your sitemap should be accessible at the URL that Odoo generates, typically https://yourwebsite.com/sitemap.xml.
2. Submit your sitemap through Google Search Console:
   If you haven't already done so, go to Google Search Console and submit your sitemap there. Google will automatically re-crawl your site regularly, so you don't need to ping them for updates.
3. Make sure your sitemap is updated regularly: Odoo should handle the automatic generation and updating of your sitemap when new content is added, but verify that this process is functioning correctly in your Odoo configuration.
4. Review the lastmod tag: Google's update also emphasizes the importance of correctly using the <lastmod> tag in your sitemap, which informs them when a page was last modified. Make sure this tag is being correctly implemented in your sitemap XML.