fix: disregard TypeScript nodes when pruning CSS

[Rich-Harris]

Fixes #14204 — this refactors get_possible_element_siblings to make it non-recursive, and use context.path and fragment.nodes rather than node.parent and node.prev. We should now be able to get rid of all references to those properties, but I'll do that in a separate PR.

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🦋 Changeset detected

Latest commit: 732da83

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pnpm add https://pkg.pr.new/svelte@14446

[trueadm]

Nice! This code is simpler to read too.