Remove webpack HardSource plugin
Remove webpack HardSource plugin

Getting various errors from it, it's no longer maintained: https://github.com/mzgoddard/hard-source-webpack-plugin.

owid/owid-grapher,owid/owid-grapher,owid/owid-grapher,OurWorldInData/owid-grapher,owid/owid-grapher,owid/owid-grapher,OurWorldInData/owid-grapher,OurWorldInData/owid-grapher,OurWorldInData/owid-grapher,OurWorldInData/owid-grapher