CVE-2023-40590: GitPython untrusted search path on Windows systems leading to arbitrary code execution

When resolving a program, Python/Windows look for the current working directory, and after that the PATH environment (see big warning in https://docs.python.org/3/library/subprocess.html#popen-constructor). GitPython defaults to use the git command, if a user runs GitPython from a repo has a git.exe or git executable, that program will be run instead of the one in the user’s PATH.