Remove `@playwright/test@next`

[Rich-Harris]

Describe the problem

Ref #4479. In order to run Playwright in TypeScript projects with a playwright.config.ts file, we need to use @playwright/test@next, hence this file: https://github.com/sveltejs/kit/blob/master/packages/create-svelte/shared/%2Bplaywright%2Btypescript/package.json

Ideally we'd be using a stable version instead.

Describe the proposed solution

Remove the file once 1.21 is released

Alternatives considered

No response

Importance

nice to have

Additional Information

No response

[JackDra]

Ref to keep track of playwright 1.21 release: https://github.com/microsoft/playwright/releases