See https://developers.google.com/search/blog/2023/06/sitemaps-lastmod-ping for context. Accordingly removed all references to notification config and/or ping.
Misc upgrade of module code so that site map.xml provides a index site map file based on the standards. Moved configuration vars to the Config API. Considering how large a change this is, I've branched a 1.0 release off in github.
jareddreyerss
Will Rossiter
Loz Calver
Will Rossiter