fix: attach __svelte_meta correctly to elements following a CSS wrapper

[Rich-Harris]

spotted while working on #15538 — if we insert a <svelte-css-wrapper>, it desyncs the template from the locations array, meaning the __svelte_meta object (which allows things like the inspector to work) is attached to the wrong element

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🦋 Changeset detected

Latest commit: d2aec37

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

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svelte	Patch

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Playground

pnpm add https://pkg.pr.new/svelte@15982

[svelte-docs-bot]

Preview: https://svelte-dev-git-preview-svelte-15982-svelte.vercel.app/

[Rich-Harris]

self-merging to unblock #15538