Describe the bug

When building with Vite 8 (which uses Rolldown), the following deprecation warning is emitted during the build:

[warn] inlineDynamicImports option is deprecated, please use codeSplitting: false instead.

The warning originates from build_service_worker.js in @sveltejs/kit, which unconditionally sets inlineDynamicImports: true without the isRolldown guard that index.js already uses.

Reproduction

Describe the bug

When building with Vite 8 (which uses Rolldown), the following deprecation warning is emitted during the build:

[warn] inlineDynamicImports option is deprecated, please use codeSplitting: false instead.

Reproduction

Any SvelteKit project with a service worker, built with Vite 8.

Root cause

build_service_worker.js unconditionally sets inlineDynamicImports: true in its Rollup output options:

https://github.com/sveltejs/kit/blob/main/packages/kit/src/exports/vite/build/build_service_worker.js

This is the Rolldown-compatible equivalent that should be used instead, similar to how index.js already handles the isRolldown check:

- inlineDynamicImports: true
+ inlineDynamicImports: is_rolldown ? undefined : true,
+ ...(is_rolldown ? { codeSplitting: false } : {})
` `` 

### Versions

- `@sveltejs/kit`: 2.55.0
- `vite`: 8.0.0

### Logs

```Shell
09:49:41.130 [warn] `inlineDynamicImports` option is deprecated, please use `codeSplitting: false` instead.

System Info

System:
    OS: macOS 26.3.1
    CPU: (16) arm64 Apple M4 Max
    Memory: 12.33 GB / 64.00 GB
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 24.14.0 - /opt/homebrew/bin/node
    Yarn: 4.9.2 - /opt/homebrew/bin/yarn
    npm: 11.11.1 - /opt/homebrew/bin/npm
    pnpm: 10.32.1 - /opt/homebrew/bin/pnpm
  Browsers:
    Chrome: 145.0.7632.160
    Firefox: 148.0.2
    Safari: 26.3.1

Severity

annoyance

Additional Information

No response