Update gix to 0.84

[cruessler]

This is a follow-up to #2962.

[extrawurst]

@cruessler what does it take to mark this as out-of-draft?

[cruessler]

@extrawurst ssh-key is still a release candidate at 0.7.0-rc.10. I’m fine with merging as-is, but I wanted to at least have mentioned it. With respect to changes related to gitoxide, there’s nothing left on my to-do list.

[extrawurst]

@cruessler there is a new ssh-key rc. still no release. a gitui crates release would fail with this - so i opt to wait :(

[cruessler]

Since #2464 got merged which removed the dependency on ssh-key, there’s no need any longer to wait for its new release, so this PR is now finally ready for review!

[extrawurst]

@cruessler any particular improvements or unlocks we will get from this now?

[cruessler]

Yes! This enables sha256 for gix. I’ll soon open a follow-up PR that enables unstable-sha256 for git2 at which point we should have support for SHA-256 repositories in gitui. Based on what I know, most, if not all, APIs we use should already work with SHA-256 without us having to change anything.