`experimental.async` does not apply to dependency code

Describe the bug

When using async components, the dev server fails to start with the error shown below, even though experimental.async: true is set.

Workaround: add optimizeDeps.exclude: ['dependency-with-async-component'] to vite.config.

Reproduction

StackBlits

Logs

deriveds and template expressions, or at the top level of a component, unless the `experimental.async` compiler option is `true`
https://svelte.dev/e/experimental_async [plugin vite-plugin-svelte:optimize-module]

    node_modules/@sjsf/sveltekit/dist/rf/client/client.svelte.js:75:34:
      75 │    const initialValue = $derived(await getInitialValue());
         ╵                                   ^

  The plugin "vite-plugin-svelte:optimize-module" was triggered by this import

    node_modules/@sjsf/sveltekit/dist/rf/client/index.js:1:14:
      1 │ export * from './client.svelte.js';
        ╵               ~~~~~~~~~~~~~~~~~~~~


    at failureErrorWithLog (/home/projects/p6pycmm1/node_modules/esbuild/lib/main.js:1457:15)
    at eval (/home/projects/p6pycmm1/node_modules/esbuild/lib/main.js:916:25)
    at eval (/home/projects/p6pycmm1/node_modules/esbuild/lib/main.js:1335:9) {
  errors: [Getter/Setter],
  warnings: [Getter/Setter]
}

System Info

System:
    OS: Linux 5.0 undefined
    CPU: (7) x64 Intel(R) Core(TM) i9-9880H CPU @ 2.30GHz
    Memory: 0 Bytes / 0 Bytes
    Shell: 1.0 - /bin/jsh
  Binaries:
    Node: 20.19.1 - /usr/local/bin/node
    Yarn: 1.22.19 - /usr/local/bin/yarn
    npm: 10.8.2 - /usr/local/bin/npm
    pnpm: 8.15.6 - /usr/local/bin/pnpm
  npmPackages:
    svelte: ^5.41.0 => 5.41.1

Severity

annoyance

Start with the linked StackBlitz reproduction and the vite.config workaround, then trace the dependency through the vite-plugin-svelte:optimize-module path shown in the logs. Confirm how experimental.async is handled for optimized dependency code and verify that the reproduction starts without excluding the dependency.