https://www.mediawiki.org/w/index.php?oldid=6100737 prints that extension has been deprecated.
However, I do not see a reason to delete the repository, at least, I cannot find it via the links on the page.

Where can I retrieve the last version of E:OpenID?

I have own copies in some wikis, but wanted to start (a different) task from the last archvied and reviewed version.