Avoid creating unnecessary temporary cat file sub process (#33942)

Extract from #33934 

In the same goroutine, we should reuse the exist cat file sub process
which exist in `git.Repository` to avoid creating a unnecessary
temporary subprocess.

This PR reuse the exist cate file writer and reader in
`getCommitFromBatchReader`.
It also move `prepareLatestCommitInfo` before creating dataRc which will
hold the writer so other git operation will create a temporary cat file
subprocess.

modules/git/repo_tree_nogogit.go

@@ -35,7 +35,11 @@ func (repo *Repository) getTree(id ObjectID) (*Tree, error) {
 		if err != nil {
 			return nil, err
 		}
-		commit, err := tag.Commit(repo)
+
+		if _, err := wr.Write([]byte(tag.Object.String() + "\n")); err != nil {
+			return nil, err
+		}
+		commit, err := repo.getCommitFromBatchReader(wr, rd, tag.Object)
 		if err != nil {
 			return nil, err
 		}