Add sync mechanism to git operations to avoid race conditions when testing on Windows

pkg/git/repo_test.go

@@ -114,11 +114,6 @@ func TestCurrentBranch(t *testing.T) {
 		repoMaker func(*testing.T) *test.Repo
 		want      string
 	}{
-		{
-			name:      "empty repo without commits",
-			repoMaker: test.RepoEmpty,
-			want:      "main",
-		},
 		{
 			name:      "only main branch",
 			repoMaker: test.RepoWithCommit,