fix: remove svelte css transform

[bluwy]

Fixes sveltejs/kit#4125

I can't seem to transfer it over to this repo. GitHub seems to have issues.

[dominikg]

i tried to do this locally yesterday but had some issues testing that it works as expected.

Ideally we'd add an e2e test that adds 3 transform plugins (pre, regular, post) that do both css and js transforms to a test svelte component and see that they all actually do work.
In addition to a regular vite+svelte setup a similar test for sveltekit may be needed too.

In a broader sense i wonder if there is a way to build a testsuite to validate that vite plugins behave per spec.

[bluwy]

I actually haven't tested this in a vite/sveltekit project, so adding a test case for this would be a great idea 😄 I can try a transform test for that.

[bluwy]

Added vite plugin tests for the hmr and kit-node e2e tests. All seems to be working fine now.

In a broader sense i wonder if there is a way to build a testsuite to validate that vite plugins behave per spec.

I think VIte has the potential for testing those explicitly in the plugin container spec file, but it's not a lot of coverage right now. The e2e tests sort-of close the gap over time.