Replacing git2 with gitoxide

[blinxen]

I recently took over the maintenance of the bat package in Fedora and was wondering if the maintainers would be willing to accept a PR that replaces the usage of git2 with gitoxide. git2 is a pain to deal with and since I am also maintaining the gitoxide stack in Fedora, it would ease the maintenance a lot .

[keith-hall]

I personally would be in favor of dropping the dependency on libgit2 and use a more performant Rust implementation 👍

[keith-hall]

Motivation: #3029 (comment)

[sharkdp]

I'd also be okay with this.