Ensure peer variants don't include multiple ~ characters

[RobinMalfait]

This PR will ensure that the peer variants are generated correctly.
Currently, the generated peer variants will result in something like:

.peer:disabled:focus:hover ~ ~ ~ .peer-disabled\\:peer-focus\\:peer-hover\\:border-blue-500 {}

But this PR will ensure that the result looks like this:

.peer:disabled:focus:hover ~ .peer-disabled\\:peer-focus\\:peer-hover\\:border-blue-500 {}

While testing, I noticed that prettier properly reduces ~ ~ ~ to a single ~. This sort of explains why the output in a production build for Next.js is "correct". The included minifiers will properly do this correctly as well, but it is incorrect in dev mode.

Fixes: #4726