Uninstalling an extension does not remove its features

Steps to reproduce:

• on a 4.3-RC1 jetty+hsqldb package install from the UI ircbot using the normal search (NOT advanced search).
• the bot version found is 4.2 (I guess it should be 4.3-RC1)
• install the ircbot extension ( version 4.2)
• uninstall ircbot version 4.2 with all its dependencies (pirc extension also)
• use advanced search and search ircbot version 4.3-RC-1 (org.xwiki.platform:xwiki-platform-ircbot / 4.3-rc-1)
• after finding it, you will get an upgrade button
• notice that even the previous 4.2 version was uninstalled using UI, it still appears as installed
• clicking on "Upgrade" button will cause an error and failure

Image attached