Usage inside CSS

When using vue, svelte, ... or other frameworks, often images are part of styles:
```css
<style>
.rice-drum {
    background-image: url(../components/static/Rice_Drum.jpg?format=webp);
}
</style>
```
vite resolves and bundles these images properly, but it seems imagetools doesn't see them - they stay in the source format and are not transformed.

Is this expected?