Remove archived plugins from gatsbyjs.com/plugins

[samscarsella]

I just spent a day trying to get gatsby-source-firestore to work with an old site I upgraded from Gatsby v2 to v4 before noticing that the plugin is no longer maintained and doesn't support Gatsby 3 or 4. Can this be de-listed from the plugin library, or perhaps there could be a 'compatibility' section of the plug-in page to help users determine what will work with their project?