Add `inverted-colors` variant

[lukewarlow]

Add a variant for the inverted-colors media query.

This has been supported in Safari for a while. I'm also implementing support in Chrome atm.

I've decided to only add the inverted-colors: inverted variant because the none state isn't really useful.

[RobinMalfait]

Hey!

You might have noticed that I forced pushed to this branch. The reason is because the PR now uses next as the base branch which is our working branch for Tailwind CSS v4. In other words, the feature you implemented here is now written in the new codebase.

The code is ported as-is, so no API changes of your feature happened while moving it to the new codebase.

I also made sure to add you as a co-author because you still deserve all the credit 💪