support vite 6

[bluwy]

In Vite 6, CSS in SSR no longer returns a default export of the processed CSS itself. Consumers need to do foobar.css?inline to retrieve that instead. This aligns with the same behaviour in the client-side but Vite had forgot to make the change for SSR, but did so in Vite 6: vitejs/vite#17922

This PR adds support for the virtual CSS to accept ?inline (and any queries in general) to be resolved and loaded. I handled all kinds of queries instead of only ?inline as other queries like ?url could also be useful, or if some plugins want to attach some metadata to the id. But I'm happy to make it strict to handle ?inline only if you prefer so.

Ref withastro/astro#12616

[mayank99]

Thanks so much for investigating this and submitting a PR! 🙏

I'll run some manual tests tomorrow and make a release after that