fix: return updated layout data if child uses parent

[eltigerchino]

fixes #9355

This PR changes the server data to return the updated layout data from a layout node if a child load function uses parent. Previously, the child load function would receive the updated data from parent, but the layout node would still return the stale data.

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Latest commit: b2880fa

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

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@sveltejs/kit	Patch

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