Forgejo is in fact working on being decentralized, just like the underlying git structure is. There are some first federation things in there, but the full implementation is still pretty far out.

While that is a really nice list, and I will save it for the future - I don’t think OP was looking for Lemmy applications, seeing as they mention they are:

using Friendica Mastodon Sharkey, Pixelfed and bridgy with bluesky

Don’t have a horse in the race myself (since I use arch, btw) but e.g. here is a compiled list of some past issues.

Same, love rdddddddddtrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrc