Remove polyfill for Custom Properties

[reesscot]

Is your feature request related to a problem? Please describe.

We recently ran into a bug with the postcss-custom-properties plugin used by @nuxtjs/tailwindcss. The maintainer of the postcss-custom-properties plugin quickly fixed this issue (thanks @romainmenke!) but also mentioned that using this plugin is no longer necessary.

Describe the solution you'd like

Would like to have the postcss-custom-properties removed from the build.

Describe alternatives you've considered

N/A

Additional context