Created by: endiliey
Motivation
Fix #6723 (closed)
When running react-scripts build on Windows Subsystem for Linux, the webpack build will hang during the uglifying step. This is caused due to a bug on terser not being able to run in parallel on WSL
(https://github.com/webpack-contrib/terser-webpack-plugin/issues/21)
This PR attempts to disable parallel run on WSL until that bug is fixed upstream