fix: keep spread non-delegated event handlers up to date

[dummdidumm]

#15961 introduced a regression where non-delegated events that were spread and updated were not getting updated. This fixes that by ensuring prev is actually updated to the most recent value

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[changeset-bot]

🦋 Changeset detected

Latest commit: ffded12

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
svelte	Patch

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[svelte-docs-bot]

Preview: https://svelte-dev-git-preview-svelte-16180-svelte.vercel.app/

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Playground

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