I had the same problem today. Try installing sass-loader v10.0.5 instead:
npm install -D sass-loader@10.0.5 node-sass
I also got this error when install sass-loader.Fix it by the reference here: https://github.com/laravel-mix/laravel-mix/issues/2562
Need to add --legacy-peer-deps to resolve it.
--legacy-peer-deps