upgrade git-repository 0.30 to gix 0.36

[Byron]

This upgrade is mainly to benefit from the new names of all git-* crates which now share the gix- prefix, with gix naturally being what was formerly git-repository.

Now there is no need anymore to rename crates in order to get the git namespace, instead we refer to gitoxide as gix from the get-go.

[o2sh]

Thanks @Byron 👍

BTW, do you have an ETA for the "git status/pending changes" support in gitoxide? Once we have this final piece, we'll be able to completely abandon git2 at last.

[Byron]

Interestingly I thought exactly the same when doing this PR, just one more feature to go!

Unfortunately I have to follow priorities dictated by cargo for this half of the year which doesn't include this feature. Fortunately though, we don't have to wait that long as @pascalkuthe has already indicated interest in the task and I couldn't be more excited - helix is waiting for this feature too and I know we are going to get a high-performance, state-of-the-art implementation once he gives it a go 🎉.