Duplicate Fonts in Bundle only on electron:build

[Clocktown]

Describe the bug
npm run electron:build duplicates local fonts, creating a bundle that contains them in fonts as well as in css/fonts. This also results in a larger asar package.

To Reproduce

vue create my-project
cd my-project
vue add electron-builder
npm install roboto-fontface

And then add import "roboto-fontface/css/roboto/roboto-fontface.css" to src/main.js

Expected behavior
Should produce the same bundle that npm run build does, which only contains the fonts in the fonts folder.

Environment:

• OS and version: Windows 10
• node version: v12.16.1
• npm version: 6.13.4
• vue-cli-plugin-electron-builder version : vue-cli-plugin-electron-builder@1.4.6
• electron version: ^6.0.0

[nklayman]

I added the duplication a few years ago because I was having font import errors on electron:build. Since the error appears to have disappeared now, I have removed the duplication in the 2.0.0 beta as it could possibly be a breaking change.