Generated types invalid for routes with a rest parameter

[TravisSpomer]

Describe the bug

The automatically generated types file for routes with a rest parameter are incorrect.

If you create a file called [...foo].svelte and then inspect the [...foo].d.ts file that gets generated, you'll see that the code isn't valid:

// this file is auto-generated
import type { Load as GenericLoad } from '@sveltejs/kit';
export type Load<Props = Record<string, any>> = GenericLoad<{ ...foo: string }, Props>;

If the ... in front of foo in GenericLoad is removed, the generated code would be valid and correct.

Reproduction

Just create a file called [...foo].svelte in any project. It doesn't need to have any contents.

System Info

System:
    OS: Windows 10 10.0.19044
    CPU: (8) x64 Intel(R) Core(TM) i7-7700K CPU @ 4.20GHz   
    Memory: 21.02 GB / 31.93 GB
  Binaries:
    Node: 16.14.0 - C:\Program Files\nodejs\node.EXE        
    Yarn: 1.22.5 - C:\Program Files (x86)\Yarn\bin\yarn.CMD 
    npm: 8.5.1 - C:\Program Files\nodejs\npm.CMD
  Browsers:
    Edge: Spartan (44.19041.1266.0), Chromium (99.0.1150.39)
    Internet Explorer: 11.0.19041.1566
  npmPackages:
    @sveltejs/adapter-static: ^1.0.0-next.29 => 1.0.0-next.29
    @sveltejs/kit: ^1.0.0-next.296 => 1.0.0-next.296
    svelte: ^3.46.4 => 3.46.4

Severity

annoyance+ (it's a compilation error that might break builds in some environments)