避免使用系统自带git下载发布版文件

[donghaiwang]

如果没有默认git，运行会报错：

(base) PS C:\workspace\hutb> & "C:\Program Files\anaconda3\envs\carla_cpp\python.exe" c:/workspace/hutb/Util/download_from_git.py
Traceback (most recent call last):
  File "C:\Program Files\anaconda3\envs\carla_cpp\lib\site-packages\git\__init__.py", line 296, in <module>
    refresh()
  File "C:\Program Files\anaconda3\envs\carla_cpp\lib\site-packages\git\__init__.py", line 287, in refresh
    if not Git.refresh(path=path):
  File "C:\Program Files\anaconda3\envs\carla_cpp\lib\site-packages\git\cmd.py", line 860, in refresh
    raise ImportError(err)
ImportError: Bad git executable.
The git executable must be specified in one of the following ways:
    - be included in your $PATH
    - be set via $GIT_PYTHON_GIT_EXECUTABLE
    - explicitly set via git.refresh(<full-path-to-git-executable>)

All git commands will error until this is rectified.

This initial message can be silenced or aggravated in the future by setting the
$GIT_PYTHON_REFRESH environment variable. Use one of the following values:
    - quiet|q|silence|s|silent|none|n|0: for no message or exception
    - warn|w|warning|log|l|1: for a warning message (logging level CRITICAL, displayed by default)
    - error|e|exception|raise|r|2: for a raised exception

Example:
    export GIT_PYTHON_REFRESH=quiet


The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "c:/workspace/hutb/Util/download_from_git.py", line 24, in <module>      
    import git
  File "C:\Program Files\anaconda3\envs\carla_cpp\lib\site-packages\git\__init__.py", line 298, in <module>
    raise ImportError("Failed to initialize: {0}".format(_exc)) from _exc       
ImportError: Failed to initialize: Bad git executable.
The git executable must be specified in one of the following ways:
or no message or exception
    - warn|w|warning|log|l|1: for a warning message (logging level CRITICAL, displayed by default)
    - error|e|exception|raise|r|2: for a raised exception

Example:
    export GIT_PYTHON_REFRESH=quiet

[donghaiwang]

Git版本高，解决：https://github.com/OpenHUTB/hutb/tree/refs/heads/git_files