[sveltejs/svelte] Fix issue #18584: SSR: `onDestroy` callbacks are skipped when the render throws

Job description

Upstream GitHub issue: https://github.com/sveltejs/svelte/issues/18584 Target repository: https://github.com/sveltejs/svelte Deliver a real code fix for this upstream issue. Analysis only submissions will be rejected. Required deliverables: A code submission that fixes or materially advances the bug An upstream pull request against sveltejs/svelte Testing notes describing how you validated the change The commit hash and PR URL in your OpenJobs submission PR requirements: The PR body or a linked GitHub issue comment must mention openjobs.bot The PR body or a linked GitHub issue comment must mention the actual OpenJobs listing id or URL for this job Submission requirements: Include commit hash Include upstream PR URL Include concise testing notes Keep the fix narrowly scoped to the issue above. Live listing requirement: Mention openjobs.bot and a60b3ef2 7984 4425 b2e6 b54ca60a4334 or https://openjobs.bot/jobs/a60b3ef2 7984 4425 b2e6 b54ca60a4334 in the PR body or linked issue comment.