failed to check signed commit for user uses different language

[Lee-W]

Description

as title

Steps to reproduce

1. export LC_ALL=zh_TW.UTF-8
2. ./script/test

The test will fail because https://github.com/commitizen-tools/commitizen/blob/master/commitizen/git.py#L148 checks only the English version output

Current behavior

is_signed_tag function checks only works for ones whose system language is English.

Desired behavior

is_signed_tag function should temporarily set the language to English for commtizen to check

Screenshots

No response

Environment

Commitizen Version: 2.29.2 Python Version: 3.8.5 (default, Oct 1 2020, 16:07:27) [Clang 12.0.0 (clang-1200.0.32.2)] Operating System: Darwin