Fix LESS compatibility for the Magento/luma theme

[ubermanu]

[PluginError: Operation on an invalid type in file Magento/luma/web/css/source/lib/_responsive.less line no. 64]

  extract: [
    '    print {',
    "        .media-width('min', @screen__m);",
    '    }'
  ],

[ubermanu]

The LESS codebase of Magento is not fully compatible with the latest version of LESS

Could be nice to specify which LESS version to use in the plugin

[ubermanu]

2ecd918