refactor!: remove go-git backend (#39487)

Removes the go-git backend so every build uses the git CLI backend. Its
Windows performance advantage is gone, it lacks SHA-256 support, and it
breaks repositories on Windows.

The performance changes moved to
https://github.com/go-gitea/gitea/pull/39526.

Fixes https://github.com/go-gitea/gitea/issues/38359
Fixes https://github.com/go-gitea/gitea/issues/34694

---------

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

modules/git/pipeline/namerev.go

@@ -16,7 +16,6 @@ import (
 )
 
 func fillResultNameRev(ctx context.Context, repo git.RepositoryFacade, results []*LFSResult) error {
-	// Should really use a go-git function here but name-rev is not completed and recapitulating it is not simple
 	wg := errgroup.Group{}
 	cmd := gitcmd.NewCommand("name-rev", "--stdin", "--name-only", "--always").WithRepo(repo)
 	stdin, stdinClose := cmd.MakeStdinPipe()