[ci][python] fall back to producing one wheel for macOS and drop support of OSX 10.6 and 10.7 (#1826)
[ci][python] fall back to producing one wheel for macOS and drop support of OSX 10.6 and 10.7 (#1826)


microsoft/LightGBM,microsoft/LightGBM,microsoft/LightGBM,microsoft/LightGBM,henry0312/LightGBM,henry0312/LightGBM,henry0312/LightGBM,henry0312/LightGBM,microsoft/LightGBM,henry0312/LightGBM