chore: reuse playwright cache for platform tests

[teemingc]

follow up to #16387
I missed adding it to the platform tests

[pkg-svelte-dev]

Install the latest version of @sveltejs/kit from f4ca929:

pnpm add https://pkg.svelte.dev/@sveltejs/kit/c/f4ca929d69be9ef602cac753fcd7fab6964ec951

Open in pkg.svelte.dev: https://pkg.svelte.dev/repos/kit/pr/16399

[changeset-bot]

⚠️ No Changeset found

Latest commit: f4ca929

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