chore: Remove unused dependency on favicons-webpack-plugin. (#1351)

This dependency depends on the `favicons` library which depends on
`sharp` which depends on a native library.

This complicates the build process as the library is built from source
because there's no binary available for my macOS Catalina
installation. As this is a common developer setup I expect others to
run into this issue as well, which is why I opted to fix this issue.

Co-authored-by: Danny Brown <danny.ri.brown@gmail.com>
Co-authored-by: Erik Ziegler <erik.sweed@gmail.com>

package.json

@@ -73,7 +73,6 @@
     "eslint-plugin-react": "7.x",
     "eslint-plugin-react-hooks": "1.5.0",
     "extract-css-chunks-webpack-plugin": "^4.5.4",
-    "favicons-webpack-plugin": "^1.0.2",
     "html-webpack-plugin": "^3.2.0",
     "husky": "^3.0.0",
     "jest": "^24.8.0",