Allow eslint-webpack-plugin ^4.0

[evertharmeling]

eslint-webpack-plugin:^4 dropped support for node:12 and eslint:7, this library already is on higher versions ("node": ">=14.0.0" and "eslint": "^8.0.0"), so this should not be a problem.

Or should we still support eslint-webpack-plugin:3 too?

[stof]

This dev dependency should stay compatible with the range allowed in the peer dependency.

And reducing a peer dependency range is a BC break, so support for eslint-webpack-plugin v3 must be kept until the next major version of Encore.

[weaverryan]

Thanks @evertharmeling!