20230913 setup GIT_PYTHON_GIT_EXECUTABLE for GitPython

@echo off

if not defined PYTHON (set PYTHON=python)

if defined GIT (set "GIT_PYTHON_GIT_EXECUTABLE=%GIT%")

if not defined VENV_DIR (set "VENV_DIR=%~dp0%venv")

set SD_WEBUI_RESTART=tmp/restart

if [[ -z "${GIT}" ]]

then

    export GIT="git"

else

    export GIT_PYTHON_GIT_EXECUTABLE="${GIT}"

fi

# python3 venv without trailing slash (defaults to ${install_dir}/${clone_dir}/venv)